SOLVED Problem IC Sunflower Fuzz

[coccoslash]

Hello to all,
I've a problem with the Sunflower Fuzz. The pedal worked great with a MAX1044 IC.
After a month the IC stopped working so I changed with a TC1044S. The pedal now works but there's a continuous whistle.
I tried all the 5 IC of the box with the same problem.

What can I do?
Thanks

 

[Nostradoomus]

Where did you get the tc1044? 100% positive they have the S designation?

 

[coccoslash]

Ebay (China).
Here a photo. Can I use, eventually, a ICL 7660SCPAZ? Thanks

IMG-20200206-182029 hosted at ImgBB

Image IMG-20200206-182029 hosted in ImgBB

ibb.co

 

[Nostradoomus]

Yes you can, as long as they have the S designation they should be fine. Do yourself a favour and buy your chips from a legit seller like Mouser or Digi-Key, not all stuff from China is bad but we’ve all been burned with fakes before. I bought 25 7660s and only 5 of them were legit, for example.

 

[zgrav]

Use your digital multimeter to make sure you have a connection between pin 1 and pin 8 on your charge pump IC. If that is connected and you are hearing a whine you likely have bad chips and can fix your problem by replacing them with something from another source.

 

[Nostradoomus]

Also I would redo your ground pad, looks like a not so great connection. Try to get those stray wires in the pad.

 

[zgrav]

Assuming you get that whine fixed, see if the replacement IC manages to last more than a few weeks. If it doesn't (or if you discover the chip gets hot when you are using the pedal) you may need to do a bit more troubleshooting to find and fix the cause.

 

[coccoslash]

Use your digital multimeter to make sure you have a connection between pin 1 and pin 8 on your charge pump IC. If that is connected and you are hearing a whine you likely have bad chips and can fix your problem by replacing them with something from another source.

Yes, 1 and 8 are connected.
Ok I try with the 7660 and see what happens, thanks!

 

[coccoslash]

It works! With the 7660 (from Tayda) no noise, no whistle. Yuppie! ?
Now I'll see if this IC will be ok for the next months ?
Many thanks!!

 

[Nostradoomus]

Good to hear! That whistle is a telltale sign something is up with the charge pump chip.