# Mach 1 no sound when engaged



## ADAOCE

Have a Mach 1 that has no sound at all when engaged. Bypass and LED work fine. I’ve checked my solder joints. Didn’t see any cold looking joints. I touched up a few resistors so that the solder penetrated both sides. I even tried a different opa2134 and a tl072.

I’ve recorded the following IC voltages with the opa2134

1: 4.46
2: 5.03
3: 0
4: 0
5: 0.16
6: 0.59
7: 4.46
8: 8.2

I’ve attached some pictures of the board from the top side. I know it could use an IPA wipe down but to be honest that’s never resulted in an issue like this for me and I’ve done ones that looked worse.

mill have to wait til tomorrow to get a picture of the underside (I stupidly didn’t take a picture when I pulled it out to reflow joints). Underside looks better than top though since that’s the side I soldered from.

anyways I’m just hoping these ic voltages are enlightening. TIA


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## Mcknib

What's the voltages on the empty IC1 socket

I'd check VREF points on the schematic pins 1 and 7 outputs seem about right with 8.2v going in, 3, 5 and 6 look way off

You should have half the power supply at the junction of R101 and 102 the voltage divider and at all your VREF points less voltage drops through resistors etc


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## ADAOCE

Mcknib said:


> What's the voltages on the empty IC1 socket
> 
> I'd check VREF points on the schematic pins 1 and 7 outputs seem about right with 8.2v going in, 3, 5 and 6 look way off
> 
> You should have half the power supply at the junction of R101 and 102 the voltage divider and at all your VREF points less voltage drops through resistors etc


Empty socket

1: 0
2: 0
3: 0
4: 0
5: 0
6: .18
7: .1
8: 8.2


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## ADAOCE

8.9 coming into D100 and 8.2 coming out

Also 8.2 going into R101 but only .47 coming out

.47 at R2 R3 and R12. Didn’t check the two other Vref spots because the caps are under the board but it would appear the issue is the voltage divider


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## ADAOCE

Could it be the electrolytic caps?


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## ADAOCE

Both R101 and R102 are reading 4.2k. The other Mach 1 thread suggests there is probably something being grounded. 

No dc voltage from input tip to ground


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## Mcknib

Your problem from what you're saying starts at R101 double check the solder joints R101, 102 and C101

It could be any of those components shorting or bridged

I wouldn't worry about resistance readings you won't get accurate readings in circuit most of the time


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## ADAOCE

Mcknib said:


> Your problem from what you're saying starts at R101 double check the solder joints R101, 102 and C101
> 
> It could be any of those components shorting or bridged
> 
> I wouldn't worry about resistance readings you won't get accurate readings in circuit most of the time


Ok thanks I’ll take a look this afternoon


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## ADAOCE

Ok update I reflowed those resistors and cap. One of the resistors did have a big blob of solder sitting on top of the joint so that was probably it. The voltage still isn’t right but when I engage the pedal I get sound. It sounds pretty good except now it appears the volume and drove pots need to be almost fully clockwise for me to get volume. Tone control appears to work just fine.

should I reflow the pot lugs?


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## Chas Grant

Recheck IC1 with empty socket. Mainly pins 3, 6 and 8. With ic removed these should have voltage on them. Pins 3 and 6 should be around 4Vdc and pin 8 should be >8Vdc. Pin 7 will have voltage also if pin 6 has it.


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## ADAOCE

Chas Grant said:


> Recheck IC1 with empty socket. Mainly pins 3, 6 and 8. With ic removed these should have voltage on them. Pins 3 and 6 should be around 4Vdc and pin 8 should be >8Vdc. Pin 7 will have voltage also if pin 6 has it.



Hey thanks I’ll report in the morning when I get back to my bench


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## ADAOCE

Chas Grant said:


> Recheck IC1 with empty socket. Mainly pins 3, 6 and 8. With ic removed these should have voltage on them. Pins 3 and 6 should be around 4Vdc and pin 8 should be >8Vdc. Pin 7 will have voltage also if pin 6 has it.



Empty  ic1

1: 0
2: 0
3: 0
4: 0
5: 0
6: 0.18
7: .1
8: 8.2


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## Chas Grant

OK those didn't change from the initial readings earlier. With out the 4 to 5 volts on pins 3 and 6, this circuit will not work right. I'm assuming you still have .47 between R101 and R102 also. You also stated you have 4.7K across R102, it should be 5.6K. You may have a leaky cap. The most likely culprit would be C101, hard to check it in the circuit, or there is a partial short somewhere, maybe on backside of board. Its also possible to create a short in the residual solder flux, it traps small particles of solder in it and can create a short, for good measure try and clean it up with alcohol and toothbrush. From what I can see on the pics, it doesn't appear that you have cold solder joints, I can see where the solder flowed through from the back side, which is good.

If your careful you can lift the board out of the enclosure with out de-soldering power connections.  Give it a good cleaning front and back and check backside of board for possible short. With board out of enclosure check voltages on IC socket with out IC. If there is nothing obviously shorted and voltage of Vref is still low then double check R101 and R102 solder joints from the back, if good then you need to check the caps. C1 and C2 can't be ruled out per se`, but highly unlikely as Vref would be a little higher. C101 is a pain to check, you would have to remove it from the circuit. Since its a power filtering cap, the circuit will work without it, there may be a lot more noise is all. So if you remove it, check the same voltages on the IC socket without the socket. If they are still low without C101, then thats not it and will have to regroup and form new plan of attack. Which is a normal thing in electronics trouble shooting, go after the most probable thing, then weed your way down.


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## ADAOCE

Chas Grant said:


> . ... normal thing in electronics trouble shooting, go after the most probable thing, then weed your way down.



Ok great and thank you for the help man. I’m going to get the board out tonight and clean it with some ipa and try these other suggestions. I’ll probably just desolder the power connection so it’s easier to clean. Getting pretty good at using solder wick now.


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## Chuck D. Bones

Let's see some pix of the back side of the board.  Higher resolution / magnification if possible.


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## Chas Grant

Chuck D. Bones said:


> Let's see some pix of the back side of the board.  Higher resolution / magnification if possible.


It's more of a challenge with out the pics


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## ADAOCE

Ok here are some pics. I was having a hard time getting detailed close up but I think I see one joint that looks pretty bad. R3 I believe. Also do you think R101 and R102 look like too much solder?


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## ADAOCE

I know angle of pics can be deceiving but I’ve checked and there are no obvious components shorted to other points. Def not ruling out a short due to flux residue


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## ADAOCE

Am I snipping leads too close?


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## Chas Grant

OK the R3 connection is questionable, reflow that. Also the R2 connection on the inside of the board, it has a ball shape to it in pics, this is a sign a joint could be cold. Both R2 and R3 would keep voltage from pins 3 and 6. Add a little solder to R3 and reflow R2, with as much solder as there is on R2, you shouldn't have to add any solder to it. Just touch the iron to it until it melts and flows nicely.


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## ADAOCE

Have a Mach 1 that has no sound at all when engaged. Bypass and LED work fine. I’ve checked my solder joints. Didn’t see any cold looking joints. I touched up a few resistors so that the solder penetrated both sides. I even tried a different opa2134 and a tl072.

I’ve recorded the following IC voltages with the opa2134

1: 4.46
2: 5.03
3: 0
4: 0
5: 0.16
6: 0.59
7: 4.46
8: 8.2

I’ve attached some pictures of the board from the top side. I know it could use an IPA wipe down but to be honest that’s never resulted in an issue like this for me and I’ve done ones that looked worse.

mill have to wait til tomorrow to get a picture of the underside (I stupidly didn’t take a picture when I pulled it out to reflow joints). Underside looks better than top though since that’s the side I soldered from.

anyways I’m just hoping these ic voltages are enlightening. TIA


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## ADAOCE

Chas Grant said:


> Just touch the iron to it until it melts and flows nicely.



Ok so reflow these joints then clean board and test voltages again? Then keep going down your list of tests? Unfortunately I don’t have another 22u cap if that is bad. Would a 47u or 10u be sufficient. I could always just deal with noise until I get a 22u


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## Chas Grant

ADAOCE said:


> Unfortunately I don’t have another 22u cap if that is bad. Would a 47u or 10u be sufficient. I could always just deal with noise until I get a 22u


Should be able to. the 10u should work, you may hear a little more noise or "hum". The 47u should work also, but never seen the first cap smaller than second cap. Normally I see like 100u and 47u. My gut says a 47 should work, but then my gut could be hitting the crack pipe right now!


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## ADAOCE

Ok I’ll try all this and report back. Thanks guys


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## Chuck D. Bones

For both C100 and C101, more capacitance is better, within the physical constraints of fitting them in the box.  Use what you have, but don't go changing parts unless you know they are bad.  Otherwise, you'll end up damaging the board swapping out parts that don't need to be swapped out.

Those photos aren't too helpful; most of the solder joints are out of focus.  You get better pix when the board and focal plane are nearly parallel.


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## ADAOCE

Chuck D. Bones said:


> You get better pix when the board and focal plane are nearly parallel.



Ok thank you. I’ll take better pics when I open it back up tonight


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## ADAOCE

Chas Grant said:


> form new plan of attack..



Unfortunately this is where we are at now. I reflowed the suspected components and got rid of any cold looking joints and really cleaned up the board as best I could (tough with the pots on the board). No change for any of this. I took out C101 and still no change.

Here are some pictures from after all of this.


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## ADAOCE

Higher quality


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## Chas Grant

DARN IT!!! Thank You for pulling that cap though! Based on the info you provided C101 was high on my list. Here was the reasoning. On R101 8.2V on top but .47V on bottom, this is your main issue, could be caused by short to ground anywhere in Vref path, open on R101(resistor or cold solder joint), leaky cap(C101 due to how low voltage is) or something loading down voltage divider hard. But you stated that both R101 and R102 read 4.2K, in my book both of those are good, there can be parallel paths in the circuit that lower the resistance of the voltage divider network, Since this is designed with an OPA2134 then they most likely took the time to account for this and the 4.7K and 5.6K both are 4.2K in completed circuit which will put Vref at half of Vcc. This to me is good engineering. Now if the 4.2K on those 2 resistors is accurate, then a cold solder joint on R101 or short around R102 is low on the list, either one of these would drastically change the resistance. It doesn't mean that's not the problem, just lowers them down the list. Now when you pulled the IC from the socket, you removed the most obvious parallel paths and reduced the possible paths for a short. I don't know the internal resistance\impedance of the power supply stage or the output stage of the op amp, so get it out of the equation. It should be high, but but not to high, but I have seen it lower than what I expected on some op amps. With the op amp removed, still no Vref on it at any pin, so this points back to voltage divider. The one component you can't check in the voltage divider circuit is C101, and it keeps popping up as a suspect, that is why I asked it to be removed. Just rename that cap Keyser Soze`!   

OK enough of that, I could keep going but you still have a non functioning pedal, and this is a humdinger of an issue. I normally like to troubleshoot with voltages, it's just how I learned and it is easier on the small PCB cause you can clip the black lead to ground and just worry about read lead. But I want check continuity. So if you could take the following real quick.
R101( the side you had 8.2V on) to pin 3 of ic socket (to be safe make sure no ic in socket)). Should be 434.7K
Same spot on R101 to pin6 of IC socket, Should be 433.9K

The next 3 should have a very high or open resistance
R101 to R11 Open
R101 to R12 Open
R101 to pin3 of tone pot. 
Please post findings when ever you can. If the radings are low you can try to isolate it y using schematic


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## ADAOCE

Chas Grant said:


> .
> R101( the side you had 8.2V on) to pin 3 of ic socket (to be safe make sure no ic in socket)). Should be 434.7K
> Same spot on R101 to pin6 of IC socket, Should be 433.9K
> 
> The next 3 should have a very high or open resistance
> R101 to R11 Open
> R101 to R12 Open
> R101 to pin3 of tone pot.
> Please post findings when ever you can. If the radings are low you can try to isolate it y using schematic



Ok so R101 to IC3 is 431k
R101 to IC6 is 8.5k

Open on all three (R101 to R11, R12 and pin3 tone)


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## Chas Grant

Crap, R101 to IC 6 should be about 9.5K so 8.5 is OK, my bad higher math kicked my butt. So all these look good. Everything is pointing back to voltage divider, try to measure resistance across R101 and R102. You should be able to get this from backside +9 and ground pads


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## ADAOCE

Chas Grant said:


> Crap, R101 to IC 6 should be about 9.5K so 8.5 is OK, my bad higher math kicked my butt. So all these look good. Everything is pointing back to voltage divider, try to measure resistance across R101 and R102. You should be able to get this from backside +9 and ground pads



Ok so the original number for R101 to IC6 of 433.9k was wrong? Damn I was hoping we found our issue! 

By resistance across R101 and R102 do you mean measure the resistance on the + and - side of the voltage divider itself? That’s how I’m understanding it since the divider has ground and Vcc on either side.


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## Chas Grant

ADAOCE said:


> Ok so the original number for R101 to IC6 of 433.9k was wrong? Damn I was hoping we found our issue!
> 
> By resistance across R101 and R102 do you mean measure the resistance on the + and - side of the voltage divider itself? That’s how I’m understanding it since the divider has ground and Vcc on either side.


Yes!! It’s the easiest way to measure the resistors and it also checks continuity through that part of the circuit


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## Chas Grant

One other thing, when taking the measurement, red lead to 9v and black to ground pad, this way you forward bias the diode


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## ADAOCE

Chas Grant said:


> Yes!! It’s the easiest way to measure the resistors and it also checks continuity through that part of the circuit



I get 4.67k across R101 and 5.56k across R102 and 10.25 with a leads on the inner sides of R101 and R102


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## ADAOCE

Chas Grant said:


> One other thing, when taking the measurement, red lead to 9v and black to ground pad, this way you forward bias the diode



If input the leads on these two points I get about 19k for a moment then OL


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## ADAOCE

FWIW I get 3.87k between IC6 and the divider (after R101 and R102) but nothing between the same point and IC3


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## Chas Grant

ADAOCE said:


> If input the leads on these two points I get about 19k for a moment then OL



That’s not what I was expecting! But it could mean we are close. Recheck the last measurement 9V pad and ground pad. If you check it and it goes right to OL that’s ok. It may, if C100 can’t discharge.


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## ADAOCE

Chas Grant said:


> That’s not what I was expecting! But it could mean we are close. Recheck the last measurement 9V pad and ground pad. If you check it and it goes right to OL that’s ok. It may, if C100 can’t discharge.



19.9k then right to OL and then did it again and got 15.5k then right to OL


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## Chas Grant

Alrighty then, you may have an open in power supply section. When you measured from the voltage divider to pin 3 and  pin 6 of the ic which resistor did you measure from?


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## ADAOCE

Chas Grant said:


> Alrighty then, you may have an open in power supply section. When you measured from the voltage divider to pin 3 and  pin 6 of the ic which resistor did you measure from?



Ah dunce cap my meter is not auto ranging I get 427k from either R101 or R102 to IC3


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## ADAOCE

Have a Mach 1 that has no sound at all when engaged. Bypass and LED work fine. I’ve checked my solder joints. Didn’t see any cold looking joints. I touched up a few resistors so that the solder penetrated both sides. I even tried a different opa2134 and a tl072.

I’ve recorded the following IC voltages with the opa2134

1: 4.46
2: 5.03
3: 0
4: 0
5: 0.16
6: 0.59
7: 4.46
8: 8.2

I’ve attached some pictures of the board from the top side. I know it could use an IPA wipe down but to be honest that’s never resulted in an issue like this for me and I’ve done ones that looked worse.

mill have to wait til tomorrow to get a picture of the underside (I stupidly didn’t take a picture when I pulled it out to reflow joints). Underside looks better than top though since that’s the side I soldered from.

anyways I’m just hoping these ic voltages are enlightening. TIA


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## ADAOCE

They are about 4.7k less than the ohm reading on the other side of R101... makes sense


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## Chas Grant

That is alright, the only time when everything goes right is when your not trying


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## Chas Grant

ADAOCE said:


> They are about 4.7k less than the ohm reading on the other side of R101... makes sense


If you go from one side of R101 then the other side of R101 then about 4.7K is right, thats R101


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## ADAOCE

Thank you for your help I really appreciate it. I am learning a little here... I think. So could a bad component be causing the open circuit?


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## ADAOCE

Chas Grant said:


> 4.7K is right, thats R101



Yep that’s what I thought


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## Chas Grant

Yes it could, but if you took at the schematic, measuring from the 9V pad to ground pad, there are only 3 components, the 1N5817 R101 and R102. If you measure them you get ok values. If you can, try to measure the 3 components from back side of board, try to stay on solder joints only, not the leads of the components. And check the diode both ways, one way should be resistance and the other an open.


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## ADAOCE

Ok so I get OL and 9.6k on the diode. I get the right resistance values on 101 and 102 as well but it’s difficult to keep a consistent reading trying to touch the solder instead of the component leads. Touching the leads it’s the right value and is consistent


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## Chas Grant

You should get clean readings on the solder pads, unless the solder joints are cold. Zooming in on the pics they get blurry, and on some the joints look ok and on others I can clearly make out the lead, which could be a cold joint. Try to reflow R101 and R102. After touching the joint, wait till you see the solder melt, then count to 3 or 4 before removing the iron. No pause or Mississippi's on the count, just a normal 1 2 3...


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## ADAOCE

Ok I’ll go give that a shot... gotta get some heat my garage lol


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## Chas Grant

I hate winter time!!! Luckily I have a work space in my house.


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## ADAOCE

Chas Grant said:


> I hate winter time!!! Luckily I have a work space in my house.



I’m working on that!


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## ADAOCE

Reflowed R101 and R102 and D100 and there’s no change


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## Chas Grant

WTF


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## Chas Grant

OK lets check continuity of board, 
BTW I'm not used to taking this kind of a butt whooping from electronics, so its a good one. 
If you measure between the colored circles, you should have near zero ohms readings


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## ADAOCE

Yes to all circled points for continuity


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## ADAOCE

I’ve built pedals that looked way worse than this and work flawlessly (Angry Andy Plus). This one is definitely puzzling


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## Chas Grant

I doesn't look bad, a good cleaning does wonders. And you have continuity on all those points, this should work


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## Chas Grant

...but it doesn't


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## ADAOCE

Think i have to call it for tonight. Thanks again for trying to help me out. I’ll try plugging it all back in tomorrow and seeing what it sounds like but without that Vcc/2 after the divider it really should NOT work right?


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## Chas Grant

I have a hunch, but no way to prove it, and its based on something I have only seen a few times. You could have a flakey component. Its rare but it does happen. I once troubleshot a bistable amplifier for 2 weeks before I found a component that would fail, and only under certian conditions. After replacing it the circuit worked fine. We have 3 suspects but no way to confirm definitely


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## ADAOCE

Have a Mach 1 that has no sound at all when engaged. Bypass and LED work fine. I’ve checked my solder joints. Didn’t see any cold looking joints. I touched up a few resistors so that the solder penetrated both sides. I even tried a different opa2134 and a tl072.

I’ve recorded the following IC voltages with the opa2134

1: 4.46
2: 5.03
3: 0
4: 0
5: 0.16
6: 0.59
7: 4.46
8: 8.2

I’ve attached some pictures of the board from the top side. I know it could use an IPA wipe down but to be honest that’s never resulted in an issue like this for me and I’ve done ones that looked worse.

mill have to wait til tomorrow to get a picture of the underside (I stupidly didn’t take a picture when I pulled it out to reflow joints). Underside looks better than top though since that’s the side I soldered from.

anyways I’m just hoping these ic voltages are enlightening. TIA


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## ADAOCE

Hmm so replace D100,R101 and R102?


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## Chas Grant

Have you got a 9V battery and 2 alligator clip leads?


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## ADAOCE

Chas Grant said:


> Have you got a 9V battery and 2 alligator clip leads?



I’ll grab some clip leads from work tomorrow


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## Chas Grant

I want to go in through the back door to try and find where you are losing the voltage. If you remove the op amp you can back feed power from the socket, it may show us where the issue is. Using a battery is much safer than a wall wart, thats why I want to use a battery. If there is a short, you can feel the battery as it gets hot and remove it, plus a battery won't damage the circuit as long as the IC is out


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## ADAOCE

Chas Grant said:


> I want to go in through the back door to try and find where you are losing the voltage. If you remove the op amp you can back feed power from the socket, it may show us where the issue is. Using a battery is much safer than a wall wart, thats why I want to use a battery. If there is a short, you can feel the battery as it gets hot and remove it, plus a battery won't damage the circuit as long as the IC is out



Ok sounds good. You can leave me some instructions to try or I’ll just holler when I’m home from work and can get to my bench and we can go from there

Edit: just realized tomorrow is NYE. Happy new year!


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## Chas Grant

Happy New Year, about what time will you be able to get on, I have the day off! And Happy New Year to you!


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## ADAOCE

I’ll be home around 330 but will be busy until 7 when I put my son to bed. I’ll send you a PM tomorrow evening


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## ADAOCE

Rigged this up at lunch. Will this be good? Only thing I had was this cable with a BNC connector on the other end.


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## Chas Grant

That’s perfect!!!


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## ADAOCE

I have some time if you do


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## Chas Grant

I got a little, working on a Caesar chorus


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## Chas Grant

The hardest part about this is hooking on the battery, the easy way is if you have an extra socket, you can plug it in the one on the board. If not then you need to be careful so you don’t mess up socket. Just need to hook up battery - lead to pin 4 and the + lead to pin 6 to start then we see what voltages are back to divider, hopefully we can find where you are losing it


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## ADAOCE

Ok it’s plugged in and I’m getting .64v after the divider


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## Chas Grant

What do you have on R3 both sides


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## ADAOCE

0 on both sides


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## Chas Grant

Where’s the battery plugged in at


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## ADAOCE

- on 4 and + on 6


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## ADAOCE

Wait do I need two batteries?


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## Chas Grant

No just one


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## ADAOCE

Ok good yeah I have it hooked like you said and I’ve confirmed I got 9.3v from the battery


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## ADAOCE

Have a Mach 1 that has no sound at all when engaged. Bypass and LED work fine. I’ve checked my solder joints. Didn’t see any cold looking joints. I touched up a few resistors so that the solder penetrated both sides. I even tried a different opa2134 and a tl072.

I’ve recorded the following IC voltages with the opa2134

1: 4.46
2: 5.03
3: 0
4: 0
5: 0.16
6: 0.59
7: 4.46
8: 8.2

I’ve attached some pictures of the board from the top side. I know it could use an IPA wipe down but to be honest that’s never resulted in an issue like this for me and I’ve done ones that looked worse.

mill have to wait til tomorrow to get a picture of the underside (I stupidly didn’t take a picture when I pulled it out to reflow joints). Underside looks better than top though since that’s the side I soldered from.

anyways I’m just hoping these ic voltages are enlightening. TIA


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## Chas Grant

See if you can get black lead on pin 4


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## Chas Grant

That way you are referencing battery negative


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## ADAOCE

That’s how I e been measuring the divider and R3. Black lead to pin 4 and red lead to test point


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## Chas Grant

And you have 0 volts on R3, on the side near pin 6it should be battery voltage


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## ADAOCE

Yes it’s 0 on both


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## ADAOCE

I’m measuring the wrong one hold on!


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## ADAOCE

Ok i get 9.3 on ic 6 side and .64 on the other side of r3


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## ADAOCE

9.3 on outward side of R4 and .56v on other side of R4


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## Chas Grant

Ok that’s better, gotta look at schematic real quick


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## Chas Grant

Check voltage on pin 7 real quick, just want to verify the feedback path


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## ADAOCE

.56v pin 7


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## Chas Grant

The voltage on pin 7 should be higher


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## ADAOCE

Ok so what might that indicate?


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## ADAOCE

Maybe something from C2 and to the right or R4 is pulling it down?


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## ADAOCE

0v on the other side of C2. Sorry just trying to give you info


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## Chas Grant

No I was pondering that. C2 is a coupling cap, it passes the AC signal but blocks the DC from the op amp circuit. If that cap shorts you get a loud hum out of pedal, that hum is the DC


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## Chas Grant

You have a short somewhere, question is, where?


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## ADAOCE

So the last time I played through the pedal the clipping section sounded great so I think that was working ok but the volumes were all off and I had to basically dime out volume and drove pots and then the tone pot actually made it louder as well


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## ADAOCE

Or at least made it appear louder. The volume pot had the worst behavior. It felt like tone and drove we’re doing what they were supposed to but volume was almost nothing unless cranked


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## Chas Grant

Shouldn’t have to dime it out though, that could be do to the low voltage on pin 3 and 6


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## ADAOCE

Have a Mach 1 that has no sound at all when engaged. Bypass and LED work fine. I’ve checked my solder joints. Didn’t see any cold looking joints. I touched up a few resistors so that the solder penetrated both sides. I even tried a different opa2134 and a tl072.

I’ve recorded the following IC voltages with the opa2134

1: 4.46
2: 5.03
3: 0
4: 0
5: 0.16
6: 0.59
7: 4.46
8: 8.2

I’ve attached some pictures of the board from the top side. I know it could use an IPA wipe down but to be honest that’s never resulted in an issue like this for me and I’ve done ones that looked worse.

mill have to wait til tomorrow to get a picture of the underside (I stupidly didn’t take a picture when I pulled it out to reflow joints). Underside looks better than top though since that’s the side I soldered from.

anyways I’m just hoping these ic voltages are enlightening. TIA


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## ADAOCE

I’ll give this another good cleaning tomorrow. I found a tiny little plastic bristle brush that should do much better at cleaning all the crevices. There are no visible solder bridges so it must be some tiny speck stuck in the flux somewhere.


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## Chas Grant

it could be in which case we are chasing are tails. Try some of that electronic cleaner, it works wonders, just dont spray it on the fron of board, if the cap values are just printed on it eats the ink. I spray the brush then scrub the front.


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## ADAOCE

Ok sounds good man thanks for your time tonight enjoy the rest of 2020!


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## Chas Grant

Anytime, I like a challenge, and this is a good one. Have a safe New Year!


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## ADAOCE

Cleaned the living hell out of this board and still no dice I’m just going to start replacing parts lol


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## ADAOCE

So I replaced R102 because I thought one of the joints looked suspect and then I swapped in a new C1. Am I right in the basic thinking that Vref isn’t being obtained because some component in the circuit is pulling down the voltage before it hits the IC? Are the caps the likely culprits? I can just try swapping a bunch out but I’m wondering if one or two might be more likely to cause the issue.
I’m playing it right now and the clipping section sounds really good and the volume is actually not terrible. The screwy part is that if I roll the tone all the way down it’s really quiet. I’ve tried it with other pedals like my klone and I can get some decent sounds stacking but it just seems like there’s a bass cut or volume drop when I turn the Mach 1 on. Is that typical for the lightspeed?


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