Hello I am tryig to repair a broken guitar fx unit
It was bricked and I programed a memory chip for it (25q32)
I soldered it on and it worked but only for a few minutes then the Ui functionallity started to decay slowly until it was completely dead
by resoldering the chip most of the times it works but only for a few minutes.
If I resolder and dont turn it on for an hour then it will work and decay (so time from soldering does not matter)
I checked the chip with thebios writer and it seems ok .
maybe the device is malfunctioning somewhere else but I really dont understaund why reheating the solder joints on the 8 pin bios memorys chip would cause it to temporely fix
could this be a bad capacitor?
I am not an electrisian so I dont have expiriance with repairing espesialy smd

I can not provide a schematic of the unit , it is not publikly available its main component is a ti dsp.

sorry for any bad spelling.

 

? shure that you need to re-solder it and it's not the temperature or "the time operated/ON/lapsed" issue

 

? shure that you need to re-solder it and it's not the temperature or "the time operated/ON/lapsed" issue

Temperature rise based on time operated used to be a problem in 70s era computer mainframes. The memory timing back then was tuned by a drop of solder on long, parallel PCB traces. My DECsystem 20 used to halt after running for an hour. Turns out there was a crack on one of the traces. That particular trace selected an external clock source. Which didn’t exist when the trace opened.

 

It also works for a few seconds if you leave it for a while
but then if you remove powere it dosen't turn back on unles you leave it for a while

the voltage regulator is giving 3.2 volts but my multimeter is not to be trusted ,old and kind of broken
capasitors the big ones seem to be charging when I put the multimeter on them

any Ideas of what I should look for?

 

capasitors the big ones seem to be charging when I put the multimeter on them

If you set the multimeter to resistance, it will charge a capacitor. That's actually how we used to evaluate(less than ideally mind you) capacitors for basic function. Hook an analog multimeter set to resistance across a cap. The meter should spike and then slowly drop back to infinite as it charges.

 

is it a DIY thing or it has a serial number printed somewhere - e.g - anything to identify the model

 

I've no idea what these circuits look like or whats in them but It kind of sounds like a capacitor problem to me. Maybe one on the vcc side for eeprom.