First two OD builds - two different problems

[dyermaker]

Hi everyone!

I'm new to this forum and new to pedal building altogether, so maybe I was a little naive thinking I could pull these builds off (I could've started with a simple fuzz...but I didn't!)

Troubleshooting according to the check-list found here (http://www.diystompboxes.com/smfforum/index.php?topic=29816.0)

PICS of both boards (not for the faint of heart): http://imgur.com/a/spH8a

FIRST BUILD

1. I've tested it before I wired the 3PDT switch. It doesn't work at all unless I gently move (or do something to) the gain pot. Then it works perfect. It reminds me of when you have a very faulty/cheap headphone jack that only works if you bend the cable in a way and try to maintain it in that position (see attached video). The charge pump works, and all of the pots do exactly what is expected. No particular noise as far as overdrives go. And it sounds great when it does work!

2. "Ampegulator" overdrive with 18v charge pump (SFT clone) by FuzzDog (Poodle Pedal Parts).

3. http://pedalparts.co.uk/docs/Ampegulator.pdf

3. I followed the instructions as best as I could, triple-checking the values and polarity of all components. But then again, I'm a noob...

4. N

5. N

6. N

7. Voltage of the battery itself = 8,99.
- Voltage at the circuit board end of the red battery lead = 8,99
- Voltage at the circuit board end of the black battery lead = 0

Q1
C = 8,85
B = 5,46
E = 2,96

Q2
C = 0
B = 1,30
E = 5,46

Q3
C = 8,80
B = 0,49
E = 5,45

Q4
C = 5,22
B = 0,77
E = 0

Q5
C = 8,80
B = 5,22
E = 2,93

Q6
C = around 5,30 but quickly goes to 0
B = around 1 but quickly goes to 0
E = 0

Q7
C = 8,78
B = 5,38
E =

Q8
C = 8,78
B = 5,69
E = 5,35


D1
A = 0,01
K = 2,02

Z4
A = 8,87
K = 14,14

Z5
A = 14,14
K = 16,85


I bought a multimeter, for the occasion (I realized too late that it didn't have a continuity mode) but I'll admit I have very little to no idea at all how to actually work this thing. I also had to wire the pots by myself, and it was really really difficult to to so since the board is so full of components. The solder itself is pretty crummy on both builds as you'll see.

While some may still be there, I've tried to clean as much flux as I could between the tracks of both boards.

SECOND BUILD

1. I've tested it before I wired the 3PDT switch. The circuit basically works and sounds great, I only have a tiny little problem which is the more I increase the gain, the more I start to hear a very high-pitched squealing noise (whether I plug a guitar in the input or not). "Funnily" enough, as I was testing the pedal I moved it accidentaly, and the problem was still here, but reversed! The high-pitched noise got louder as I turned down the gain pot, what about that? I tapped gently on some ramdom parts of the board and it went back to "normal". I managed to spot what looks to me like a faulty component, or something: D2 was noisy when I touched it.

2. "MegaHIWatt" overdrive (WIIO clone) by FuzzDog (Poodle Pedal Parts), NORTH version.

3. http://pedalparts.co.uk/docs/MegaWatt-V2.pdf

4. N

5. N

6. N

7. Voltage of the battery itself = 8,99.
- Voltage at the circuit board end of the red battery lead = 8,94
- Voltage at the circuit board end of the black battery lead = 0

Q1
C = 3,23
B = 0,49
E = 5,69

Q2
C= 3,15
B= 0,50
E= 5,77

Q3
C= 3,17
B= 0,49
E= 5,69


Z1
A = 3,23
K = 0,49

Z2
A = 3,13
K = 0,50

Z3
A = 3,18
K = 0,49

I apologize in advance if my multimeter readings are misleading, I'm not quite sure what to make of the results, but I sure would like any advice concerning these builds. Both make a sound, I feel I'm very close! But also very very close to giving up. I've made two video samples of the issues I have with both pedals, I'm not quite sure how to attach them to this post.

Thanks you all very much for sharing your knowledge!

[EBK]

Has to be bad solder joints causing much of your problem.  Resolder everything that is "touch sensitive".

Oh, and welcome to the forum! 

[EBK]

Jesus, your picture links tried to drive-by infect my phone!


Don't click on those links, folks!

[dyermaker]

Jeez sorry let me take those links out.

Thanks for answering. For the gain pot on BUILD n1, I've remade all of the wires connecting the pots to the board at least twice each. It's always the same pot that causes the problem. Obviously since the build is complete and I've already desoldered/resoldered too much, it's getting more and more complicated to access the components, let alone desoldering them as neatly as possible. I'll try to post pictures of the boards (anyone can suggest a virus-free pic hosting website?) FuzzDog has suggested a burned pad on the PCB. If that's true, how can it be dealt with?

[Kipper4]

For picture hosting try Imgur. There are others too.

A broken trace can sometimes be fixed.
Post up some pics please.


Welcome.

[GibsonGM]

Try IMGUR.com.    Reliable site.   Welcome to the forum, also!

If you have ok soldering skills, you can bypass a messed up pad by scraping away the insulative coating on the PCB (often green, plastic...) for a bit past it, and 'jumpering' to this now-exposed copper.    Often you can bend a component lead to make this jump...hope that makes sense.

Yeah, gotta agree - when some seems touch-sensitive, it probably is!!!  Bad solder, broken wire inside the insulation, or bad contact on the pot (but not very likely, esp. if the pot is new).

[EBK]

Until we can safely see your pics, here is a good visual guide to recognizing/fixing different types of bad solder joints for you to consider:
https://learn.adafruit.com/adafruit-guide-excellent-soldering/common-problems

[dyermaker]

Thanks for all of your answers. I've put a link with the pictures in the original post (some of these are not pretty  ). It was pretty much impossible to see what was going on underneath the vertical-mount pots on BUILD 2. On both builds I've tried to scrape as much flux off the board as possible.

@EBK: yes I've come across this website recently, but to be perectly honest, I can't tell the difference for the life of me...Of course when there's a hole on the pad and solder has not melted all around the pad and the pin, I know something's wrong. But as far as the color of the solder itself, the shape of it...

[EBK]

Pin 1 of that IC looks bent oddly....

[slacker]

On your Ampegulator there's a problem with Q6, its voltages should be similar to Q4. Might be worth checking and reflowing the solder joints around the Q6, Q7 and Q8 area. It's difficult to tell on your photo but the soldering on the middle pin of the gain pot doesn't look great maybe check that as well.

[dyermaker]

Do you reckon that with the symptoms I mentioned, any component could be faulty?

As far as the readings go, I'm not really sure they're accurate. I'll check ASAP.

Thank you everyone!

EDIT: for the IC bent pin, is it safe to do something/anything about it since what it's supposed to do (charge pump for 18v option) works perfectly?

[EBK]

If the charge pump works perfectly, don't fix it! 
I just mentioned it because I tend to debug with my eyes looking at the board first and pay attention to voltages later.

[dyermaker]

Ah I see, numbers can be misleading (especially if I've mesured those). It's more than likely fixable in both cases, what frightens me now is that all the components are in, they're fragile, I don't wanna make them go through a lot of risky desoldering. I might create other problems when trying to fix those.

Are those two particular issues common? (the first I'll say that it's a shortage, it's a question of no sound at all - the second issue is a high pitched whine/squeal increasing with the gain pot)

[EBK]

Your first issue is more likely a break than a short.  Bad solder joint(s) somewhere (I'd bet 10 magical leaky germaniun transistors on it).  Very common issue.

The whine/squeal issue is very common as well (try seeing how many hits you get searching the forum for "whine" or "squeal"  ).  Some quick checks: does it squeal if you run it on a battery? Does it squeal with no guitar input? Sometimes these are fixed with a part swap or two. Sometimes it's another bad solder joint or a bad cap.

[dyermaker]

Thank you. Is there a way to narrow down the field of experiment for the Ampegulator? Rather than reflowing every joint on the board ?

I guess as many of you have said it's more likely to be a capacitor/transistor/diode issue rather than a resistor issue. The thing is that the first problem only occurs with the gain pot, it does seem a bit surprising that I'd get the same issue on the same spot on the board having reflowed/re-wired that pot a couple of times but who knows?

For the second problem indeed I've seen countless issues like this one, most of the time being caused by a faulty IC, but there's no ICs on that second build. It does squeal even when there's nothing plugged into the input jack. I don't think I've tried running it on a battery, because it was such a pain in the %^* to safely remove the 9v dc wires on the daughterboard, and the solder, to make the hole appear again so I can fit the battery wires in (plus knowing I'll have to revert the operation to rewire the 9v dc socket back in). But if I have to I will!

[EBK]

Thank you. Is there a way to narrow down the field of experiment for the Ampegulator? Rather than reflowing every joint on the board ?

I guess as many of you have said it's more likely to be a capacitor/transistor/diode issue rather than a resistor issue. The thing is that the first problem only occurs with the gain pot, it does seem a bit surprising that I'd get the same issue on the same spot on the board having reflowed/re-wired that pot a couple of times but who knows?

For the second problem indeed I've seen countless issues like this one, most of the time being caused by a faulty IC, but there's no ICs on that second build. It does squeal even when there's nothing plugged into the input jack. I don't think I've tried running it on a battery, because it was such a pain in the %^* to safely remove the 9v dc wires on the daughterboard, and the solder, to make the hole appear again so I can fit the battery wires in (plus knowing I'll have to revert the operation to rewire the 9v dc socket back in). But if I have to I will!

1.  Could be a burned out or scratchy pot.  If you heat cheap pots too much, the film/traces can lift, or flux could seep in.  Consider replacing it.

2.  Are you using a switched DC jack?

[dyermaker]

What do you call a switched DC jack?

[EBK]

What do you call a switched DC jack?

3 solder terminals: one common (gnd), one battery+, one DC plug+.
Inserting a plug opens a switch, disconnecting the battery.

[dyermaker]

I see. Yes the two builds use those switches. So I could also solder the + wire of the battery to the leftover lug?

[EBK]

I see. Yes the two builds use those switches. So I could also solder the + wire of the battery to the leftover lug?

Small earlier has a labeled picture of what gets connected where:
http://smallbear-electronics.mybigcommerce.com/2-1-mm-all-plastic-round/