Klon KTR Repair Help

[ToneRangerAudio]

Hey all,

Long story short, the owner before me overpowered his KTR and tried to have someone fix it. The repair person put a random Zener diode in and said it didn't work, and ended up destroying the pads from overheating in the process (see pics).

So here's the dilemma, I found some spots on the board to tap into for the Zener (1N4742) and got the pedal working, however there is a squealing/whining sound when the pedal is both on and off. Do y'all think the 7660 charge pump is fried as well? I have a skilled hand and can replace parts very easily, just haven't messed with SMT IC's yet. Easy or no?

Also, if you were gonna tap into the circuit to place the Zener, where would you place it? I did mine at pin 1 of the 7660 and ground on one of the pots. Any feedback or suggestions would be great! I've attached pics and and schematic below.

[ToneRangerAudio]

Update: I confirmed the charge pump works properly by testing voltages around it. So it's not that. I'm getting audio, but also a really annoying whine.

[antonis]

Did you verify that the damage was indeed caused by overpower or by reverse polarity powered..??

[ElectricDruid]

"Annoying whine" certainly sounds like a charge pump problem. The standard 7660 runs at 10KHz which is firmly in "whine" territory. Can you have a look at the charge pump's output voltages on the scope to check them for ripple? Perhaps the charge pump caps are bad?

[ToneRangerAudio]

"Annoying whine" certainly sounds like a charge pump problem. The standard 7660 runs at 10KHz which is firmly in "whine" territory. Can you have a look at the charge pump's output voltages on the scope to check them for ripple? Perhaps the charge pump caps are bad?

I'm going to go ahead and just swap the pump. Mouser is only 30min from where I live so I'll have parts in tomorrow. I'll keep ya'll updated!