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DIY Stompboxes => Building your own stompbox => Topic started by: SirHugo on April 26, 2018, 10:51:29 PM

Title: Hello! My Zendrive has no drive!
Post by: SirHugo on April 26, 2018, 10:51:29 PM
So I got my PCB from Aion and most all my components from SmallBear. I followed the build exactly with no deviations and it appears to work correctly ( the Led, the bypass, both voice and tone) However I have no drive or volume, they work but there is little to no gain or volume, unless both are dimed, in which case it is super thin and treble-y with crackly break up. Iíve checked an rechecked all the leads and components and canít find the issue. If anyone has any insights or ideas of the issue, any help would be very appreciated, Iíve tried to figure it out for a few days and Iím going mad! For good measure Iíll add a picture of the cuicit Incase I am missing something visually.
Thanks ahead of time for any help anyone can offer!
JHK

(https://s9.postimg.cc/qpm5b9c97/276_C6_B4_A-_EBF7-460_F-_AADE-6_D7_A3_E690_D99.jpg) (https://postimg.cc/image/qpm5b9c97/)

(https://s9.postimg.cc/pakkmjybf/60259344-98_BB-431_E-8_ECA-_BDFF165_AE149.jpg) (https://postimg.cc/image/pakkmjybf/)
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on April 27, 2018, 12:52:29 AM
Here is the build doc for this pedal https://aionelectronics.com/wp-content/uploads/2015/08/aion-azimuth-zendrive-documentation.pdf
Title: Re: Hello! My Zendrive has no drive!
Post by: Kipper4 on April 27, 2018, 02:18:07 AM
Hi sirHugo.
Welcome aboard.

This will help us to help you if you go here and tell us what we need to do


http://www.diystompboxes.com/smfforum/index.php?topic=29816.0
Title: Re: Hello! My Zendrive has no drive!
Post by: thermionix on April 27, 2018, 03:53:21 AM
Only thing jumping out at me is all the melted insulation at the footswitch.  Check that nothing's shorting out.  Always a good idea to check the circuit function before wiring to the footswitch and boxing up.  Much easier to diagnose and fix if there's a problem.
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on April 27, 2018, 10:14:59 AM
Kipper thanks man Iím working on getting the rest of the info together.
Thermonix Iíll replace the melted wires and see if that helps.
Iíll post the metered components here soon.
Thanks for helping me out.
JHK
Title: Re: Hello! My Zendrive has no drive!
Post by: samhay on April 27, 2018, 11:34:20 AM
Any chance you mixed your drive and voice pots up and swapped them?
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on April 27, 2018, 03:21:34 PM
Unfortunately no, it seems as though everything is in its place. Iím going to meter the whole thing and reflow again.
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on April 27, 2018, 09:56:07 PM
Alrighty I mulitimetered the whole thing and hereís what I ended up with!
IC1 (AD712)
P1 4.86
P2 4.86
p3 4.68
p4 0
p5 4.84
P6 4.86
P7 4.86
P8 9.72

Q1 (2N7000)
C 4.72
B 4.86
E 4.86

Q2 (2N7000)
C 4.86
B 4.86
E 4.86

D1 (1N4002)
A 0
K 9.72

D2 (BAT41)
A 4.86
K 4.76

D3 (1N34A)
A 4.77
K 4.72

D4 (BAT41)
A 4.86
K 4.77

C1 (470n) 0 - 4.86
C2 (100pf) 4.86 - 4.86
C3 (100n) 4.85 - 4.85
C4 (3n3) 0 - 4.86
C5 (470n) 0 - 4.84
C6 (100uf) 9.72 - 0
C7 (47uf) 4.85 - 0

R1 (470k) 4.85 - 4.68
R2 (1k) 4.86 - 4.86
R3 (1k) 4.86 - 4.86
R4 (10k) 4.84 - 4.86
R5 (1k) 0 - 0
R6 (10k) 4.85 - 9.72
R7 (10k) 4.85 - 0
RPD (1M) 0 - 0
LEDR (4k7) 1.80 - 9.72

Drive (500k A)
1 4.86
2 4.86
3 4.86

Tone (50K B)
1 4.86
2 4.85
3 4.84

Voice (10k B)
1 4.86
2 4.86
3 4.86

Volume
1 0
2 0
3 0

LED (5mm) 1.80 - 0

Power
Tip 9.72
Ground 0



Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on April 27, 2018, 10:04:55 PM
I hope this helps I may wait to reflow Incase anything jumps out any anyone from this information
Thanks again!!
JHK
Title: Re: Hello! My Zendrive has no drive!
Post by: Kipper4 on April 28, 2018, 08:09:29 AM
Your voltages all look ok to me.
So maybe it's a switching problem. Maybe you made a gaff there.
Or something is shorting on the case.
Check the jack wiring.

Do you have an audio probe?
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on April 28, 2018, 08:55:02 AM
Ok well thatís good, Iíll triple check the switch and in/out put wiring. I do not have a probe but Iím sure I have all I need to fashion one. Hopefully the problem is in the switch/jacks. Though Iím sure I should make one either way.
What could cause shorting on the case? Anything in perticular to keep an eye out for?
Thanks
JHk
Title: Re: Hello! My Zendrive has no drive!
Post by: thermionix on April 28, 2018, 09:23:41 AM
What could cause shorting on the case?

It happens mostly with wired pots, when tightening the nut it can rotate and one lug shorts against the inside of the enclosure.  But you have board-mounted pots, so probably not your problem.

I looked at your pics the other day, and it seems your switch and jacks are all wired IAW the instructions, but I could have missed something.  There's a chance the switch was damaged by heat, going by the melted insulation.  You can possibly figure that out with a meter without disconnecting the wires.

Other possibilities include bad solder joint(s) or solder bridges.  We can't see the underside of your board.  For certain though, it's something simple, and you will get it sorted out.
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on April 28, 2018, 09:35:07 AM
Ok cool thanks man.
So hereís a thing, I get no response on the meter for the jacks on either the sleeve or tip (ofcourse the sleeve would be 0) and the live points on the switch flash .01 then 0. I assume this is not normal?
JHK
Title: Re: Hello! My Zendrive has no drive!
Post by: Kipper4 on April 28, 2018, 11:42:04 AM
That's normal to not get dc voltages on either of the jacks connections.
The input and output caps block the dc. That's partly what they're there for.
If you have a probe you can follow the signal through the circuit and trace where it goes bad .
If it's easy I'd take the board out of the box. It'll be easier to trace.
As someone pointed out it's always a good idea to test the circuit before boxing.
Rock it before you box it.
It helps narrow down the amount of possible issues if you know the board works before boxing.
For future reference
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on April 29, 2018, 12:43:22 PM
I unfortunately do not have a probe. I ha e an update though, o re-wires the switch and it was bypassing normally but then no sound with the effect on, now it seems to be humming no Nate Tre what. I have a distinct feeling that the switch is deadski.
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on April 29, 2018, 01:28:07 PM
I was wrong lol. I took off all the leads and cleaned them flipped the switch and itís working again, unfortunately the pedal is still not  working properly, itís still thin and trebley and the only way to get any sound is having the vol and gain all the way up. I would to build a probe but I unfortunately canít find a cap for it. I tried the continuity meter on my MM but it dosnt make sound it just flashes a 4digit number then goes away. Iím not sure how to read that.
So as it stands the bypass is working, LED works and effect is engaged but very thin tone and very little output. The switch seems fine. Iíve triple check my jacks and they are wired properly, all my components are working properly having been metered and catalogued several times. I need to build that probe I guess because I just canít figure this out! Thanks to everyone who has helped me out so far, this has been a frustrating experience but Iíve already learned a great deal of tips and tricks from you all and I truely appreciate it.
JHK
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on April 30, 2018, 01:11:41 PM
Well after a week Iím back at square 1. Same symptoms as when I initially posted.
Title: Re: Hello! My Zendrive has no drive!
Post by: Kipper4 on April 30, 2018, 01:49:23 PM
Post up the present voltages of the ic please.
It's more than likely something small, a wiring error etc.

Is it still in the box?

Have you an audio probe yet?
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on April 30, 2018, 02:48:59 PM
No, no probe yet, I should have a cap for it soon I have all the other bits I need to make it.
Here are my current IC voltages
IC1 (AD712)
P1 4.86
P2 4.86
p3 4.64
P4 0
P5 4.84
P6 4.86
P7 4.86
P8 9.73

I had removed it from the box while I was working on it however I put it back together as I was gonna shelf it and comeback to it with fresh eyes, and I didnít want anything getting dirty or lost. Though while it was out it was very hummy and noisy, which has gone away in the enclosure, I assume the jacks are grounding to it.
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on April 30, 2018, 02:56:14 PM
Something else I just noticed was that the LED lights weather or not there are cables on the jacks.
Title: Re: Hello! My Zendrive has no drive!
Post by: Kipper4 on April 30, 2018, 04:26:59 PM
Are you waiting for a particular cap?
Title: Re: Hello! My Zendrive has no drive!
Post by: Kipper4 on April 30, 2018, 04:36:16 PM
Something else I just noticed was that the LED lights weather or not there are cables on the jacks.

I assume from this you used a switching jack or TRS for the input.
Is this so?

It depends on input jack switching and indeed your 3pdt wiring.

Title: Re: Hello! My Zendrive has no drive!
Post by: thermionix on April 30, 2018, 06:22:16 PM
In my builds now I do it so that with a battery it needs a cable in the input jack to turn on, but with a wall wart it doesn't.  Commercial pedals (and kits) vary, with some you always need a cable in the input.
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 01, 2018, 11:21:12 PM
I think itís just a normal enclosed switch craft jack with just one sleeve and tip. It may be the wiring on the switch. Yeah Iím waiting on a cap to make the probe.
Title: Re: Hello! My Zendrive has no drive!
Post by: Kipper4 on May 02, 2018, 10:25:52 AM
You can use a 100nf ceramic cap maybe even try 47nf for the probe.
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 02, 2018, 10:34:24 AM
Ahhh 47k works?! Thatís great Iíve been hard pressed to canabalize a 100u from anything but a 47 im sure I have. Thanks!
Title: Re: Hello! My Zendrive has no drive!
Post by: thermionix on May 02, 2018, 05:42:15 PM
47k is a resistor.  Anything near 47n will work.  You don't want teeny tiny, you don't need huge.
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 10, 2018, 12:48:19 PM
Ok after a bit of a break from the zen. Iím taking it off the shelf and tinkering again, I havenít changed anything yet but I have my probe set up now with a look to check it. I am however a bit bewildered as to what I should be looking for, some points are loud some are quite and some seem to break up and almost sound pixilated for lack of a better word. I know I need to trace the schematic, but Iím unsure what a red flag might be if I come across it short of no signal what so ever.
Thanks a head of time for your help!
JHK
Title: Re: Hello! My Zendrive has no drive!
Post by: Kipper4 on May 10, 2018, 06:34:43 PM
Chill out we will do our best to get you there Sir.
Some bit of the circuit will sound different to others. Level,fuzz....... As long as you have signal  is enough for now.

So looking at the aion docs.

Ac (guitar) Signal goes in the input.
cover the basic.

Through C1 to the + (aka Non inverting) op amp input.
out of the op amp to R4 Through the tone pot (might be some signal lose here at the node of Tone lug3,C4.)
Reason being it's what we call an RC filter.

> pin5 (non Inverting) op amp input. Check this too.
check its output pin7.

Through the C5 output cap.
I suspect you will have lost signal by now.

Make sense?
Probe away.

I'll be back in the morning. Smoke me one.


Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 10, 2018, 07:05:03 PM
Thanks so much kipper! I appreciate it! Iíll scope it out, and post my findings. One thing I have noticed just probing about is that one of my BAT41 and my Germanium diode both sound like a dying battery, not sure if thatís normal or not, I suspect not but Iím still quite novice at this as you can tell. Happy to say I built a Vertex steel string clone without incident, so Iím happy about that. Hopefully the probe will illuminate the Zens malfunction.
JHK
Title: Re: Hello! My Zendrive has no drive!
Post by: chromesphere on May 10, 2018, 08:29:27 PM
Hi SirHugo,

As most others have suggested I would also recommend checking over your soldering, I can see a couple of solder joints on the 3pdt that look like they are in very close proximity.  I would check over all of your offboard wiring for errrors.

On the pcb a few things you should try:
- Look for solder bridges here as well (bottomside of pcb)
- Try replacing the AD712 with something pin compatible, perhaps a TL072, to rule out the IC as the problem.
- Check values of the resistors, caps, etc

I would suspect a soldering error though and encourage you to check over your soldering an reflow anything that looks suspicious, make sure there is adequate spacing, etc.

Hope it helps and good luck!
Paul
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 11, 2018, 10:42:52 AM
Ok Kipper hereís what I found
Input (loud) obviously
Iím on switch (quite)
Iím on board (no sound)
C1 (medium)
R4 (medium)
Tone (all lugs medium)
C4 (medium)
Pin 5 (loud/distorted)
Pin 7 (no sound)
C5 (quiet)
Volume (lug 1 no sound/Lug 2 & 3 quiet)
Out on board (quiet)
Out on switch (loud)
Out on jack (Loud)

So the other oddity Iím not sure if itís worth mentioning is that
D2 - loud + dying battery
D3 - dying battery +dying battery
D4 - no sound + dying battery
Not sure if thatís normal

Paul,
So far I have triple checked the components
Relowed twice
Iíve got a back up IC which offers no change that I can tell
So far as I can see there are no bridges
Iíve also Metered the whole board twice with no obvious issue
The 3pdt has been since cleaned up since the intial photo post
Thanks for the heads up though man, I scoped out your site and really dig it
Iím ealecially interested in the buffer and Iím loving the dial decals youíve made.

Title: Re: Hello! My Zendrive has no drive!
Post by: Kipper4 on May 11, 2018, 10:47:25 AM
There we go. Pin5 good pin7 not.
Check pins 6&7 Are connected together.
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 11, 2018, 11:24:35 AM
Alright I checked it out, but I donít see any connection between 6&7 hereís a picture for reference.
(https://s31.postimg.cc/gh8nzxyaf/C6_A73_C1_E-_EADB-4_D72-9362-_C91_BBF0_FBCCB.jpg) (https://postimg.cc/image/gh8nzxyaf/)

(https://s31.postimg.cc/o9zbrwwjr/EDD095_E2-0865-479_D-8606-_BD25_B359_DF89.jpg) (https://postimg.cc/image/o9zbrwwjr/)
Title: Re: Hello! My Zendrive has no drive!
Post by: Kipper4 on May 11, 2018, 12:02:21 PM
I can't tell from the pictures. The trace is probably internal or some such.
However you can check 6&7 are connected with your meter on continuity test mode.
Probe on 6 probe on 7..
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 11, 2018, 12:53:44 PM
Tried the continuity meter but itís not reading anything on anything lol, itís a cheapo so it dosnt create a tone even when it works itís just reading ďOLĒ and when it dose work it reads a 3 - 4 digit number but only seems to get a read off of the switch lugs. The meter works on every other setting though so Iím not sure what the deal is with the continuity setting.
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 11, 2018, 01:43:51 PM
Also I made a mistake on the list Obove,
Pin 3 on the ic is loud/distorted
Pin 5 is quite quiet
No signal on pins 6 + 7
No signal on pins 1 + 8
Pin 2 is about medium volume
Title: Re: Hello! My Zendrive has no drive!
Post by: Kipper4 on May 11, 2018, 01:45:34 PM
I found this Seymour Duncan forum.

"I posted this a while ago to help someone learn about continuity. I'm just looking for others to add their thoughts/opinions, etc. as I don't think that I write all that clearly compared to others in the forum.


"Not all meters have a buzzer/light for continuity.

If the meter is set to around 20 Kohm resistance and the test probes are not touching anything, the readout should be "0" or ".0L" .....this means that if you get this reading there is NO connection between the parts...that is, there is a loss of CONTINUITY of electrical circuit. Some meters have a continuity beeper/buzzer that will sound when there IS continuity (showing that the circuit is therefore intact) or conducting when two electrically joined parts are being tested.
If you get a small resistance reading..the circuit is intact and you are reading the resistance between the two points being tested.

CONTINUITY is one of the most useful (and simple) things you can learn to do with your meter IMHO, especially for wiring guitar circuits.

You can make a simple continuity tester with a set of probes, battery and a buzzer. Connect everything in series with the "break" in the circuit being the probes (just like a switch). When you touch the probes it buzzes...if you touch the ground at the jack and the the ground on the pot (or a ground anywhere else) it will buzz, showing that you have continuity with the grounds. A buzzer is better than a light because you don't have to look away from your testing to see if the light is on/off.

You can check your electrical connections between any two points this way.

Hope this helps."


Maybe try the ohm setting thing.

If the connection is bad you could breach the pins6,7 and test the circuit again for audio.

Let's see.

Title: Re: Hello! My Zendrive has no drive!
Post by: Kipper4 on May 11, 2018, 02:08:10 PM
Also I made a mistake on the list Obove,
Pin 3 on the ic is loud/distorted
 (that's your guitar straight.)

Pin 5 is quite quiet

No signal on pins 6 + 7

No signal on pins 1 + 8 ( pin 1 is the op amps output you should get a signal here. All of the circuits gain happens there. The resistances in the negative feedback network determine the gain.
 (AD712 is a dual op amp package. One is made up of pin 3,2,1 the other 5,6,7.)

(Pin8 is the +9v rail. I'd expect to hear dc here not our guitar signal. DC powers the componants. AC is our guitar.) Stop me if I'm "teaching my grandma to suck eggs"


Pin 2 is about medium volume

I'll quit while I'm ahead.
I'd look at the stuff around the negative feedback loop.
Have you a magnifier and light Sir?

Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 11, 2018, 02:31:28 PM
Yes I do! And thanks btw for the continuity post that was incredibly helpful, btw pin 6 and 7 together ready about 1130 or so, so I guess theyíre connected.
Title: Re: Hello! My Zendrive has no drive!
Post by: Kipper4 on May 11, 2018, 02:43:36 PM
Look around the stuff on IC1-A
everything from C3 all the diodes and mosfets, gain pot etc- to R4 with the magnifier. Check for cold solder, bad joints.
Also If you check the DC (4v5) on the Vr side of C3 please.

Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 11, 2018, 03:09:46 PM
Alrighty will do!
Title: Re: Hello! My Zendrive has no drive!
Post by: Kipper4 on May 11, 2018, 04:16:48 PM
You are reading the pins right way right?

https://en.m.wikipedia.org/wiki/Dual_in-line_package#/media/File%3APin_numbering_01_Pengo.svg
    ~
1.     8
2.     7
3.     6
4.     5



Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 11, 2018, 04:24:48 PM
Yes, I am, I double checked just to be sure but yes.
So on C3 Iím reading 4.84 on both ends
As for cold/weak joints I donít seem to see anything that looks perticularly funky
But Iím sure anouther reflow wouldnít hurt.
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 11, 2018, 04:32:19 PM
Hmm A few joints look a bit dull so they may be causing issues.
Title: Re: Hello! My Zendrive has no drive!
Post by: Kipper4 on May 11, 2018, 04:38:35 PM
Ok great.

Normal voltages you'd expect.
1.2.3.5.6.7 all around Vb. (4v5)
8 @ 9v
4 @0v Gnd

You might experience some meter loading on some pins.

4v8 is in the parish
Title: Re: Hello! My Zendrive has no drive!
Post by: Kipper4 on May 11, 2018, 04:39:41 PM
What type of solder  are you using please?

Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 11, 2018, 04:45:27 PM
Yeah, hereís the current IC reads
1 4.85
2 4.85
3 4.66
4 0
5 4.81
6 4.85
7 4.85
8 9.70

I used Rosen core radio shack solder
Title: Re: Hello! My Zendrive has no drive!
Post by: Kipper4 on May 11, 2018, 04:51:10 PM
Nice one.

Dull is not good make sure it wets.
Tin the tip. Clean and reflow.
Double check the diode orientations and mosfet.
Not that I see that being much of a problem.

Happy soldering.
Is this your first debug?
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 11, 2018, 05:02:40 PM
Yeah it is ! Iím learning a ton from it which is great! I built a BYOC mini rams head, modded a blue box, built this zen and I recently built a steel string clone but this is the first Iíve had to debug, but this experience though a bit frustrating, has been incredibly illuminating.
Iím gonna go ahead and reflow and report back!
Thanks again for your patience  in helping this novice pedal builder!
Title: Re: Hello! My Zendrive has no drive!
Post by: chromesphere on May 12, 2018, 07:18:05 AM
If that fails Hugo, (although it may seem extreme its simple to do) try testing the pcb externally from the enclosure.  Did you "rock before you boxed" as they say?  This is a very critical step.  It breaks the build up into 2 sections and makes fault diagnosing easier.  If you have tested the pcb, you would know that its 99% likely to be working and you could focus your attention on the offboard wiring.  Im not sure of this pcb's wiring scheme but im sure theres a way to test it externally from the offboard wiring.  I would suggest if you hit a brick wall to try this.  If you find the effect is working you can focus on the offboard wiring.  If you find the effect isnt working, you can focus on the effect (and not waste time with the offboard wiring).  Hope that makes sense!

Paul
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 13, 2018, 02:23:56 PM
I may have to consider it. So after reflowing all dull points it seems to me to have a bit more volume than before but now Iím assuming something may be up with the drive cuircit, at this point the bypass works fine, clean signal when bypassed and effect on when on and LED is lit, no extra noise. But the drive sounds weak. IC pins 1 + 6 + 7 still have no signal. Volume pins minus the ground now sound loader but the drive sounds tinny and thin and only really distorts when dimed. Dose any one know how I can post a video in here? I have a sound sample. Iím confused how I have volume and out put if those 3 pins on the IC have no signal, seems impossible on the schematic.
Title: Re: Hello! My Zendrive has no drive!
Post by: thermionix on May 13, 2018, 05:15:18 PM
Dose any one know how I can post a video in here? I have a sound sample.

You can't post it here directly.  You can upload it somewhere else and post a link.  You can upload to youtube and embed here with the youtube button.
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 13, 2018, 09:32:16 PM
Ah gotchas thanks!
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 14, 2018, 12:11:41 PM
Dose anyone have any idea how pins 1 6 7 on my IC could be dead on the probe but functioning via meter and still some how sending signal to the volume? This seems to be the problem thatís been plaguing me.
Title: Re: Hello! My Zendrive has no drive!
Post by: Kipper4 on May 14, 2018, 12:18:04 PM
Heres how it works.
The DC (that you're reading with the meter) Powers the componants.
The Ac that your trying to listen to with the probe (guitar signal) May have been disconected at some point. And Is not getting through from pin3 to 1
or from pin5 to 7

usually its a wrong part or bad joint somewhere.

Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 14, 2018, 12:27:17 PM
Oh ok I gotcha! Well I know my components are correct, so there must be a connection issue somewhere though I canít seem to find it. [ Invalid YouTube link ]https://youtu.be/0CRcLRJnHzA
Hereís a sound sample of it bypassed then on, please note both drive and volume are all the way up. I donít know if this will help but perhaps it will give some clues.
Title: Re: Hello! My Zendrive has no drive!
Post by: Kipper4 on May 14, 2018, 12:50:53 PM
Certainly sounds like it's working.
I'm hearing distortion right?
Only thing is it should be way louder when dimmed.
Title: Re: Hello! My Zendrive has no drive!
Post by: Kipper4 on May 14, 2018, 12:53:05 PM
Look around the R3 ,voice pot ,C3 network.

Also double check the gain pot wiring.
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 14, 2018, 02:12:00 PM
Yes thatís been my struggle, everything is working it just has some gain/bass loss somewhere. Iím probing about and hereís what Iíve found
R3 1 rounded distorted signal 2 bright distorted signal
Voice
1 distorted signal
2 distorted signal
3 distorted signal (slightly louder than the others)
C3 1 rounded clean signal 2 distorted signal
Gain
1 no sound
2 distorted signal
3 distorted signal
C2 1 no sound 2 distorted signal
R2 distorted signal on both sides
R4 1 clean signal 2 no sound
And itís not in the area but I descovered the + end of C6 has no signal


Title: Re: Hello! My Zendrive has no drive!
Post by: Kipper4 on May 14, 2018, 02:34:39 PM
Gain
1 no sound
2 distorted signal
3 distorted signal

Have you a spare pot? preferably OVER 10k value?
Could you solder it. Just asking at this stage.

Have you got a Spare resistor say 50k  100k  500k?
We could test the pot without removing it by adding some parallel resistance and see if it improves the gain. (one end of R to lug1 tother end of R to lug3)


"And itís not in the area but I descovered the + end of C6 has no signal"

C6 is in the DC power supply. It's role is to smooth out the DC ripple. Not part of the audio path.
As are all the power supply componants. Not part of the audio signal path.

Briefly
Power supply.
LEDR is a current limiting resistor for the indicator led5mm
D1 is a reverse polarity protection diode. Intended to give some protection for a short time if somebody plugs the wrong power supply to the effect.
Next is the power pins for the IC 712
C6 well we know what that does now.
The two 10k resistors form a voltage divider whos output is at the junction (node) of the two. Since they are eqaul value the voltage out will be (Vr) +4v5 (half of the available +9v power supply.
C7 It performs the same function as out C6 but this time its smoothing the Vr.

 

Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 14, 2018, 09:05:12 PM
I donít have a spare pot unfortunately but Iím sure I can canabalize something for a resistor.
Iíll try it out. Dose that mean you belive the pot is dead ? Thanks for clarification of the power section!
Title: Re: Hello! My Zendrive has no drive!
Post by: Kipper4 on May 15, 2018, 12:58:06 AM
Not sure if it's the gain pot. But it might be a quick test to rule it out.
Title: Re: Hello! My Zendrive has no drive!
Post by: chromesphere on May 15, 2018, 01:03:33 AM
Unlikely to be the pot Hugo.  I would still wager that the issue lies with an assembly error or solder / flux bridge.  I would check all joints and make sure there are no accidental connections.  Probably wouldn't hurt to remove the flux from between the pads as well. 

If you would like me to check any points for voltage on my Zen drive (madbean serendipity) please let me know and ill send them through.

Cheers
Paul
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 15, 2018, 12:13:46 PM
What is the best way to remove flux? Thereís a good deal on there from multiple reflows so that may be causing issues, at the very least itís unsigtly. My voltages seem solid, but i could do anouther check today and see if anything is amiss. But yeah despite a few reflows and a lot of probing Iíve yet to find a solution.
Title: Re: Hello! My Zendrive has no drive!
Post by: thermionix on May 15, 2018, 06:53:12 PM
I usually scratch it off with a steel dental probe type tool.  Then brush away the dust with an old toothbrush.  There are chemical sprays but they are quite expensive, and can dissolve finishes such as laquer.  A magnifying glass or jeweler's loupe is invaluable for inspecting boards for little bridges and whatnot.  Vero is about the worst, the gap between the tracks is tiny.
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 15, 2018, 09:53:02 PM
Ok cool man thanks! Iíll clean it up and report back! Thankfully the PCB isnít vero.
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 16, 2018, 12:49:00 AM
Well I removed all excess flux and cleaned the residue and... dead pedal.
It works in bypass cleanly without noise, but when the effect is engauged it mute and the LED dose not light. I re metered to see what might be up and Iíve found some oddities.
 

IC1 (AD712)
P1 4.85
P2 4.79
p3 4.60
p4 0
p5 4.85
P6 4.85
P7 4.84
P8 9.72

Q1 (2N7000)
C 4.85
B 4.85
E 4.65

Q2 (2N7000)
C 4.75
B 4.79
E 4.79

D1 (1N4002)
A 0
K 9.72

D2 (BAT41)
A 4.79
K 4.68

D3 (1N34A)
A 4.68
K 4.65

D4 (BAT41)
A 4.85
K 4.75

C1 (470n) 0 - 4.59
C2 (100pf) 4.86 - 4.79
C3 (100n) 4.85 - 4.79
C4 (3n3) 0 - 4.84
C5 (470n) 0 - 4.85
C6 (100uf) 9.72 - 0
C7 (47uf) 4.85 - 0

R1 (470k) 4.85 - 4.85
R2 (1k) 4.78 - 4.79
R3 (1k) 4.79 - 4.79
R4 (10k) 4.84 - 4.58
R5 (1k) 0 - 0
R6 (10k) 4.85 - 9.72
R7 (10k) 4.85 - 0
RPD (1M) 0 - 0
LEDR (4k7) 9.72 - 9.72

Drive (500k A)
1 4.86
2 4.79
3 4.79

Tone (50K B)
1 4.85
2 4.85
3 4.85

Voice (10k B)
1 4.79
2 4.79
3 4.79

Volume
1 0
2 0
3 0

LED (5mm) 9.72 - 0

Power
Tip 9.72
Ground 0

So yeah clearly no good having 9.72 on the LED and both sides of the LEDR. And other connections have lost a bit of current.
Title: Re: Hello! My Zendrive has no drive!
Post by: Kipper4 on May 16, 2018, 04:00:41 AM
All Dc voltages look good.
Where does the probe say the signal stops?
Go back to reply 28 my a.c. signal path and tell us where it stops
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 16, 2018, 10:54:15 AM
Iíll scope it out once Iím home, I was concerned by the meter reads because the LED  had  changed  from reading 1.80 - 0 to 9.82 - 0 and the  LEDR was 1.80 - 9.72 and now 9.72 - 9.72.
Title: Re: Hello! My Zendrive has no drive!
Post by: vigilante397 on May 16, 2018, 11:07:50 AM
I have a working Zendrive that I just finished (my own layout but using the schematic from Aion's build doc) so I can get some voltages when I get home today so you have something to compare to.
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 16, 2018, 09:28:29 PM
Yeah thanks man that would be absolutely be helpful!
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 16, 2018, 09:47:36 PM
Input (quiet)
In on switch (quiet)
In on board (loud and noisy)
C1 (both loud and noisy)
R4 (both very quiet and a little crunchy)
Tone (all three lugs quiet)
C4 (no sound and quiet and crunchy on the other side)
IC
Pin 1 (quiet and crunchy)
Pin 2 (loud but very static and crunchy)
Pin 3 (loud distorted)
Pin 5 (quiet and crunchy)
Pin 6 (quiet clean)
Pin 7 (quiet clean)
C5 (medium and clean)
Volume (lug 1 no sound/Lug 2 & 3 medium, clean)
Out on board (medium, clean)
Out on switch (no sound
Out on jack (Loud, distorted

Lol of course now the pins on the IC are working correctly
Title: Re: Hello! My Zendrive has no drive!
Post by: vigilante397 on May 17, 2018, 09:12:12 AM
Well, I have some bad news. Your voltages look great :P Aside from RLED of course.

Have you tried pulling the switch out and connecting the board straight to the jacks? Whenever I'm debugging I like to remove any and all variables and go from there.
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 17, 2018, 11:10:53 AM
Well thatís good to hear thanks for checking, and no I havenít yet but Iíll try that once Iím home, do the audio probe reads reveal any clues to anyone? As I said the IC is finally working correctly albeit quiet in places, but thereís a good deal of differences from the last time I did a probe.
Title: Re: Hello! My Zendrive has no drive!
Post by: Kipper4 on May 18, 2018, 10:47:07 AM
Is it working right now?

Is the gain above unity?

Also did you double check the diode polarity?

I'll look at doing a demo next week so you can compare.

Rich
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 18, 2018, 01:43:58 PM
So itís kinda working, I took out the switch and signal is passing through but I have a lot of noise, almost helicopter-y, tons of treble but it seems to have more low end then before.
The LED is not lighting still.
With all the noise Iím not sure if Iíve got unity gain but it seems a little Woolier than before.
I have quad checked the diode orientation.
Thanks that would be great.
I would assume with all that noise thereís a ground issue somewhere.
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 18, 2018, 02:05:55 PM
Hereís a quickie sound sample with out the switch
[ Invalid YouTube link ]https://youtu.be/dj6-kuNLbik
Title: Re: Hello! My Zendrive has no drive!
Post by: Kipper4 on May 18, 2018, 03:22:51 PM
Does it do the noise in bypass too?
Stupid question maybe.


Edit
Just plugged mine in and If i have all the knobbys cranked I can hear a bit of oscillation.
I'd say it's rare I'd have the gain past 10 Oclock.
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 18, 2018, 03:28:23 PM
Well the bypass worked fairly well when the switch was attached but itís disconnected in the sound sample
Title: Re: Hello! My Zendrive has no drive!
Post by: Kipper4 on May 18, 2018, 03:35:34 PM
Doh......

Yep.
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 19, 2018, 11:19:18 AM
Iím going to replace all the outboard wiring today and wire the switch back in, reflow and see what that dose. Iím wondering if thereís something I can use to clean the board thatís safe, and perhaps in my basement, would mineral spirits work? I have acetone aswell but Iím fearful that will eat the plastic. I scraped and brushed away the extra flux but thereís still what looks like oily residue where it was, and it was after cleaning it that this new issue with the LED began.
Title: Re: Hello! My Zendrive has no drive!
Post by: duck_arse on May 19, 2018, 11:39:13 AM
try methylated spirits. dunno what it's called where you are. it may well leave a powdery white residue, or a sticky film behind. give it another go over with clean metho and a toothbrush.

don't clean your teeth with that brush again.
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 20, 2018, 11:54:26 AM
Haha Iíll be sure not to, I think itís the same as mineral spirits and if not Iíll find it .
Thanks man
Title: Re: Hello! My Zendrive has no drive!
Post by: vigilante397 on May 21, 2018, 01:13:30 AM
Iím wondering if thereís something I can use to clean the board thatís safe, and perhaps in my basement

I just leave the flux on the board more often than not ::) but when I do get motivated and clean my boards I always use isopropyl alcohol (rubbing alcohol). Never had any problems.
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 21, 2018, 08:26:28 PM
Oh nice that I most certainly  have, really I was just cleaning it since there was a lot after reflowing several times so I worried it was causing some issues and Iíve tried a lot to fix it over the past few weeks so I figured Iíd give it a try. Iím hoping to replace all the wiring and reflowing again tonight.
Title: Re: Hello! My Zendrive has no drive!
Post by: chromesphere on May 21, 2018, 09:21:39 PM
Hi Hugo, thought I would just throw it out there but that noise isn't your power supply?  Can you power the pedal with a 9v battery and confirm?
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 23, 2018, 02:27:04 AM
Iím afraid it isnt wired to have a battery. But I have plugged in other drives and pedals into it and they dosnt make any extra noise so I think the power source is clean. I also tried a few other wall worts and power brick I have with no avail. I havenít had a chance yet to re wire and reflow yet so hopefully tomorrow I may have some updates.
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 25, 2018, 06:52:31 PM
Welp I carefully rewired all the outboard componants and itís dead Iím nearly 100% sure meter readings are all over the place, and certain spots not squeal when touched by the meter, Iím just going to re order everything and start from scratch.
Thanks for all your help
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 26, 2018, 07:13:02 PM
I have another pedal with an issue but thatís for another thred, and may be fixed with a replacement component.
Title: Re: Hello! My Zendrive has no drive!
Post by: chromesphere on May 27, 2018, 07:27:50 AM
Yeah this one turned into a tough one Hugo.  Did you end up testing the effect externally from the offboard wiring?
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 29, 2018, 11:50:26 PM
Yes it kind of worked similar to when it was originally having issues, ie thin and lots of treble and very noisy.
Title: Re: Hello! My Zendrive has no drive!
Post by: chromesphere on May 29, 2018, 11:57:10 PM
Well atleast you know the problem is isolated to the PCB.  Did you try scrapping off the flux from the pcb and reflowing any dodgy looking solder joints?  Also check the component side doesn't have any accidental connections.  You can post some up to date photos of the pcb again showing just the pcb outside of the enclosure, someone might be able to spot an error.
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on May 31, 2018, 11:55:26 PM
Hereís how itís looking now, and no light, no signal (bypassed or on) just loud hum .
There are points on it that never seem to get shiny when reflowed.
They just turn grey immediately after heat has been taken away.

(https://s33.postimg.cc/5pjr4oo5n/4_FD91565-_B0_A3-4_CC1-8085-0_D1_C994_FD478.jpg) (https://postimg.cc/image/5pjr4oo5n/)

(https://s33.postimg.cc/y2f8v5263/A7311236-145_E-4656-_BEEA-_FAF10_CEC972_A.jpg) (https://postimg.cc/image/y2f8v5263/)

(https://s33.postimg.cc/5pjr4o8q3/AF0_A409_C-_BA30-49_A4-8_F64-540_B819_FA956.jpg) (https://postimg.cc/image/5pjr4o8q3/)

(https://s33.postimg.cc/exbzld82j/B281_ED46-_E169-4_A9_E-_BBF7-_D4_AF9_B8_B5495.jpg) (https://postimg.cc/image/exbzld82j/)
Title: Re: Hello! My Zendrive has no drive!
Post by: chromesphere on June 01, 2018, 12:04:46 AM
When I say "externally from your offboard wiring" I mean, cutting the effect free from the offboard wiring.  So you have a populated pcb with in out plus and ground wires.  I use alligator clips and a simple offboard wiring diagram to check the pcb.  This isolates the pcb from any other source of a problem in the offboard wiring scheme.  Pedal builders call it "rock before you box". 

There is a test wiring diagram in one of my docs, go to page 5 "testing your effect".  Hook up populated pcb with that wiring scheme.  When you have your effect working you can just solder those four wire back together and heatshrink the bare connections so they don't short.

http://www.diyguitarpedals.com.au/shop/boms/7_Min_Fuzz.pdf

I wouldn't worry about the dull solder joints.  it doesn't matter too much as long as you have a solid connection.  Usually cold solder joints that are problematic are visually identifiable...ahem...usually... :)
Title: Re: Hello! My Zendrive has no drive!
Post by: thermionix on June 01, 2018, 12:33:01 AM
In the pics, the jack on the right doesn't have the sleeve connected.  Probably not your whole issue, as it may have been fine inside the enclosure.  But outside, you need to jumper that to ground somewhere, other jack's sleeve will do.
Title: Re: Hello! My Zendrive has no drive!
Post by: Kipper4 on June 01, 2018, 03:21:59 PM
Are you using single core wire?  Or stranded?

Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on June 02, 2018, 04:50:14 PM
Standard. I just threw a ground on that jack and now it works in bypass but itís dead dead when the effect is on, no LED and no signal, audio probe yields either no sound or squeezing. I assume something in the power area may be messed up when this issue started my LEDR read 9.72 on both sides and 9.72 on the LED itís self where as before when it lit is was sitting at 1.80.
Also when I audio probe the cuicit in bypass it seems to only have sound in the drive section and it sounds very overdriven and thick.
Title: Re: Hello! My Zendrive has no drive!
Post by: SirHugo on June 04, 2018, 11:45:11 AM
So is it dead ? I havenít re ordered anything yet. I canít tell if the PCB is a goner or just some componants.