SOLVED: Lectric-FX Zirconia (Diamond Comp clone) no sound at all

[matopotato]

A Zirconia build (https://lectric-fx.com/wp-content/uploads/2017/06/ZiRCONiACompressor_V.1.1.pdf) fails to have any effect. I did have some issues with changing D1 "ripple limiting" diode from one side of the PCB to the other and my soldering station decided to fail without telling. But I have tested it and it seems to be OK, and its place in the circuit is fine. But it made me check the power section and all is either 9.6V, 4.71V or 0V in the expected places. Except C1 which has 0V and 0.57V. I have some basic knowledge of physics, and to me all components connected to the VA - R1 "line" should have the same potential with power on, but not C1. Polarity is according with how the cap is marked, and I think I would have noticed a shorter leg on plus if it was a dud...
This spills over somehow to pin8 on IC2 (OP275). So instead on pin4 and 8 having 0 and 9.6V, pin8 shows 0.57V. However IC1 (LM358) has pin4 and 8 as wanted, 0V and 9,6V. Again, I cant see how that is possible, but those are the readings I get.

I traced with an audio probe and it checks out until pin5 on IC2.2 (OP275) although a bit faint. Pins 6 and 7 are quiet.
I measured the OP275 with no audio, just power and I get about 1.07V on each pin except pin4 (0V) and pin8 (0.57V) as mentioned above.
I also swapped the ICs, and the only change was the the audio signal on pin5 on IC2.2 (now temporarily the LM358) got louder and a bit more clear. I think that has more to do whit the characteristics of the ICs and didn't think this would be part of the problem.

[matopotato]

[matopotato]

Forgot to mention: I did not put in the HiCut DIP nor the C29 3n3 cap. This should be intended for cutting treble and that part goes to ground anyway, so I plane to change the DIP to an SPDT(?) with On-Off-On and possibly two other caps to ground so I get some more noticeable effect than what the 3n3 has (I could tell while breadboarding).

During breadboarding I did not get all functions to work, but the EQ-BP switch was made up of wire and jumpers so I did not pay much attention to it. I had breadboarded 2 times before without getting it to work. But 3rd time ti seemed to work so I decided to put it together.

[idy]

If C1 is not showing a voltage find out why. If it is soldered in and correct polarity, maybe there is a broken trace (maybe the diode reworking?)

Power off, check for continuity from C1+ to the power rail. Check for continuity from C1- to ground.

But that is not the problem killing your sound, just good housekeeping.

Next, if pin 8 of IC2 is not getting power, that would be your problem. Again, power off, check for continuity from the place where there is power (VA) and pin 8. Also check for a short to ground (continuity pin 8 to ground, not likely.)

I suspect there is a break in the trace/eyelet that connects VA to pin 8. Interesting you are getting the same wrong voltage on C1 and pin 8. Coincidence?

Reworking a board it is very easy to pull an eyelet out or lift a trace. Solder gob shorts also easy.

[matopotato]

Thanks, will try.
I think an eyelet could have come out of the D1, but I checked for continuity on D1 legs vs R1 and ground and it checked out, so I thought I had solder enough to make the connection.
Or is a lost eyelet a lost connection, so I should jump with some wire from D1 legs to ground/R1?

So I tried again, and you are right (well, I was not expecting anything less having helped med with Spectron previously)
There is no continuity from D1 to R1/VA and neither from C1+. Not sure how both would have lost it, but assuming the eyelet served more than one connection. Oddly, I remember the other D1 eyelet being the lost one. On the other hand it was sitting on the leg when I put it back, so maybe it found its way.
I will cable C1+ and D1 Cathode with R1.

Many thanks, and fingers crossed.

[idy]

Bits of component leads we snip off after soldering, those we retrieve ad use to connect things that need to be connected.

But wait, what do you mean R1? R8 maybe?
And what do you mean D1 and the R(8?) to ground? Not that! That is your power. Don't connect it to ground.

And did you make sure C8 is soldered in? Correct polarity? You need to see voltage on its + pin. That is supposed to be VA.

Eyelets (the plating through the holes) can be pulled out or merely broken free from the traces around them. Then you may get intermittent power/signal.

To review: Power comes to D1. You should see .2V less on the cathode. Then R8. You should again see a tiny bit less. + of C8 you should see the same. That is VA. You should see that same V on both opamps pin 8.

Maybe you are not testing conituinty right. Your meter beeps on the setting, sometimes a picture of a diode? Short the leads and it beeps?

Visually inspect: find out where the trace for VA goes. It attaches to both ICs. One of them is getting power, the other not. Something is missing. You will be able to see the trace snaking around under the solder mask.

[matopotato]

I'm lost. Sorry. I have no R8.
I use https://lectric-fx.com/wp-content/uploads/2017/06/ZiRCONiACompressor_V.1.1.pdf
In the upper left corner on page 4, the schematic I have +9V coming in , then R1 of 100R. The other side of R1 does connect to D1, C1, C22, IC1, IC2, C30, R2, which all make up VA, the near 9V potential
There is a split for C31, R3 and C3 that make up the VB, which seems to be about half of VA.
The "1" of R1 that goes to all of the first listed ones mean to me they should have the same potentials, and connectivity. So C1 and D1 did neither. The potential being off surprised me. The lost connectivity less so.
My plan is to wire from D1 cathode plus side, and C1 plus side to meet the R1 labelled "1" on the other side of the "official" 9V high potential start. it seems to tie in with the schematics.

C8 is way over to the "end" after the switch and close to R38 and the HiCut. It seems unrelated to power at all...

The power in my case does not seem intermittent, just wrong values.

"Maybe you are not testing conituinty right. Your meter beeps on the setting, sometimes a picture of a diode? Short the leads and it beeps?"
I think you lost me here...
It beeps when I cross "the beams" or touch places that are connected and should be so.

VA goes to pin 8 on both ICs, the OP275 had 0.57V but the LM358 had proper 9-ish V

All in all I found that without powering up, there was no continuity between D1 "C" and C1 "+" and R1 "1" and they should be connected according to schematics, so tomorrow I'll wire them together and see if that changes anything. I am grasping and hoping it will result in OP275 getting proper power and then work, and the rest follows. The OP275 is kind of the first Op-Amp that the audio signal sees, after it there are all kinds of ways to go and switches and what not, so I am hoping this will help.

[idy]

Sorry, I think I was thinking of a different thread! Wrong numbers... I am replying to two different threads you have started....

[idy]

OK, different issues. The Zirconia. D1 is not ripple limiting, it is reverse polarity protection, but works the "other way from the one in your  Azimuth. Here it shunts power to ground if the polarity is wrong.

You should see continuity from diode Cathode(stripe) to the + of the Cap. But if that diode is not soldered in the circuit should still function, just not protected against reverse power.

So you have confirmed that you have 9v(or close) at VA and 1/2 that at VB? Then you are done trouble shooting the power supply section and should not mess with it. The big question is why Op275 (IC2) is not getting 9v to its pin 8.
Socket not soldered well?
Chip not pressed in, leg bent?
Trace from VA to pin 8 broken?

Power off, check continuity from VA to pin 8 of IC2. That is where you might end up adding a jumper. Possibly at the diode (or near it) the two chips get their power from different traces, maybe on opposite sides of the board. So a damaged trace might let power get to one chip and not the other.

[matopotato]

Sorry, I think I was thinking of a different thread! Wrong numbers... I am replying to two different threads you have started....

Thanks, yes might have been it. I have no Azimuth though. Might be another OP as well?
I saw now it is another thread where I made a reply yesterday

[matopotato]

OK, different issues. The Zirconia. D1 is not ripple limiting, it is reverse polarity protection, but works the "other way from the one in your  Azimuth. Here it shunts power to ground if the polarity is wrong.

You should see continuity from diode Cathode(stripe) to the + of the Cap. But if that diode is not soldered in the circuit should still function, just not protected against reverse power.

So you have confirmed that you have 9v(or close) at VA and 1/2 that at VB? Then you are done trouble shooting the power supply section and should not mess with it. The big question is why Op275 (IC2) is not getting 9v to its pin 8.
Socket not soldered well?
Chip not pressed in, leg bent?
Trace from VA to pin 8 broken?

Power off, check continuity from VA to pin 8 of IC2. That is where you might end up adding a jumper. Possibly at the diode (or near it) the two chips get their power from different traces, maybe on opposite sides of the board. So a damaged trace might let power get to one chip and not the other.

I checked the ICs and sockets.
I suspect it is more related to the moved D1 and the repercussions. Will jumper wire around it to get continuity.
I just dou le checked and the D1 Cathode, C1 + and the IC pin8 should all be on the VA rail, but no connectivity. All three connect between themselves though. So one wire from say D1 Cathode, back to the rail ought to bring them back. Which supports your suggestion that there are more than on rail trace on the PCB. I got tricked by the schematics and not being aware of multiple tracings.

The frustrating thing was, I  was all done, but fitting the jacks was a real challenge. Not until then did I read that you could put D1 on the other side.
So I went to desolder using my very new soldering station. I managed to suck up most of the solder and when prying the legs out it so happened that the station failed and got cold. And I thought it was just a matter of a last push.
I also got the station since my previous pen would be uneven in where the heat was right, so many things together ended up me pulling the legs out without enough heat to them.
Had I been soldering instead I thinknI would have noticed that the station was broken.
Being brand new the shop gave me a new one with no hazzle.

[antonis]

I suspect it is more related to the moved D1 and the repercussions. Will jumper wire around it to get continuity.

I shouldn't do it..
(it will get R1 in parallel with power supply..)

[matopotato]

Thanks for all help in this.
I wired D1 Cathode side to the "proper" R1 side. This also made the OP275 pin8 and C1 + connect to the rail. So now it works!
I did a mod after that and replaced the DIP and 3n3 cap for high cut with an SPDT (on off on) and 6n8 and 15n instead allowing for more high cut. Not sure about how needed it is but 6n8 and 15n make has much more bit somewhat subtle impact than 3n3.
With no compensation it can bit a bit hissy. On the other hand, the EQ can compensate for most.
Not sure why there is a switch for EQ on or off when the EQ at noon sounds the same as when it is off...
So the EQ DPDT will most likely be always on for me.
The pedal sounds really good. A bit more subtle than I had expected, but will be no problem.
The drill template could be made so the in out jacks get more room, and possibly push the pcb up a bit so that the pots and knobs sit a bit nicer.

[matopotato]

I suspect it is more related to the moved D1 and the repercussions. Will jumper wire around it to get continuity.

I shouldn't do it..
(it will get R1 in parallel with power supply..)

Hmm, Connecting the D1 cathode to the R1 on the "right" side is the way the schematics have it?
Anyway, it worked an they all get their 9V now and it sings.
I think my jumpering just made sure that the D1, C1 and pin8 on OP275 all meet at some point in the rail. Be it on the R1 "1"/right side or any of the other components meeting in the rail shouldn't really matter as far as I can tell?

[antonis]

My bad..
I though you want to jumper D1 (short it)..

[matopotato]

My bad..
I though you want to jumper D1 (short it)..

Ah, no. Then I'd have left it out and be without polarity mistake protection.
But managed to get it back in.
Thanks for alerting non the less