Informant overdrive problems

[ElReverendoRyan]

Hey guys.

Had some trouble with the informant. First it worked out of box, then didn’t once in box, then it did, then I’d get oscillation from the voltage doubler, then ONLY that sound + IC2 is heating up. All of this out of box now mind you.

I’m kinda running out of ideas and getting tired of looking/proving, my eyes are shot to s*** (been at it for 3 hours now). Anyone wanna take a look at these pics see if I’m missing something?

 

[ElReverendoRyan]

As you say, all the values look good!
When you magnify the PCB there is quite a bit of flux & solder bits on the back of the Board.
Would be a good idea to Clean with Electronic Cleaner and under Tone pot, there may be a stray bit of crap or you might find a bad joint!
The other thing is we can't see your Footswitch or Jack connections on the PCB or Off the PCB???

All that flux has been cleaned since

Here’s a bigger angle

 

[ElReverendoRyan]

All that flux has been cleaned since

Here’s a bigger angleView attachment 23406

What I don’t get is that it worked great, even boxed, and all of a sudden just went back to that oscillation, and I can’t bring it back. It’s definitely something power related, because when I unplug it you hear the squeal « power down »

 

[music6000]

It wouldn't be the first time a TC1044SCPA went south, I personally don't use them!!!
I use a 7660SCPAZ, Pull one TC1044S from a working pedal & try that!
You should have no Continuity on the IC Pins other than Pictured below:

 

[ElReverendoRyan]

It wouldn't be the first time a TC1044SCPA went south, I personally don't use them!!!
I use a 7660SCPAZ, Pull one from a working pedal & try that
You should have no Continuity on the IC Pins other than Pictured below:

View attachment 23407

Cheers, will check this

 

[ElReverendoRyan]

It wouldn't be the first time a TC1044SCPA went south, I personally don't use them!!!
I use a 7660SCPAZ, Pull one TC1044S from a working pedal & try that!
You should have no Continuity on the IC Pins other than Pictured below:

View attachment 23407

The 7660SCPAZ is a direct drop in? With the solder connection at the back?

 

[music6000]

The 7660SCPAZ is a direct drop in? With the solder connection at the back?

Yes!

 

[ElReverendoRyan]

It wouldn't be the first time a TC1044SCPA went south, I personally don't use them!!!
I use a 7660SCPAZ, Pull one TC1044S from a working pedal & try that!
You should have no Continuity on the IC Pins other than Pictured below:

View attachment 23407

Continuity test checks out

 

[music6000]

Continuity test checks out

ALSO Pin 8's on IC1 & IC2 !!!

 

[ADAOCE]

Yes!

Do you have to bridge pins 1 and 8 on the 7660 when replacing a 1044? I thought only the lt1054 needs to have the pins bridged

 

[music6000]

No, No Bridging for LT1054 only!

 

[jesuscrisp]

ICL7660S needs to have the pins 1 and 8 connected.

 

[ADAOCE]

ICL7660S needs to have the pins 1 and 8 connected.

Right but PPCB circuits that call for tc1044 also accept 7660 and don’t require additional soldering only for the 1054 do you need to bridge the pads on the back. I was just checking. I’m swapping a 7660 in another build because I can’t find 1044s right now

 

[ElReverendoRyan]

I’ve ordered new charge pump and tl072s. Everything else checks out. I’ll keep you posted

 

[ElReverendoRyan]

Alright!

Switched the type of charge pump, and had a spare 4558 lying around. It worked, but after a while the sound would fizzle out, until i jiggled the op amp at IC1. Reflowed, same. Let it play like that (running a loop of guitar into it), and bridged connections on the op amp to adjacent parts, found a pin that would spring the circuit to life. Soldered a jumper and let the loop run for 15 minutes, didnt seem to have the issue afterwards. Gonna wait a bit before declaring victory, but its looking good

 

[fig]

Alright!

Switched the type of charge pump, and had a spare 4558 lying around. It worked, but after a while the sound would fizzle out, until i jiggled the op amp at IC1. Reflowed, same. Let it play like that (running a loop of guitar into it), and bridged connections on the op amp to adjacent parts, found a pin that would spring the circuit to life. Soldered a jumper and let the loop run for 15 minutes, didnt seem to have the issue afterwards. Gonna wait a bit before declaring victory, but its looking good

Hot dog!
What pin did you connect to? I'm following along in the shadows.

 

[ElReverendoRyan]

Hot dog!
What pin did you connect to? I'm following along in the shadows.

3 to the adjacent resistor