I was working on a build, following CyberPit XH-543 Mods
All I've done so far is my own mod, removing the onboard pots (I have 10k pots on the signal input side) and bridging the two pins necessary for it to work.
I was testing it after doing that mod, 600hz sine wave and had audio output, 10.5volts AC across the output leads when my external pots were turned off (they were backwards). I turned it off and flipped around my pots and turned it back on, it was working correctly.
I had set the heat sink ontop of the chip and accidentally knocked the board, I saw a spark on C26, a 1uf cap I believe according to XH-543 diagram, and now I have no output at all.
I replaced it with one of the ceramic 1uf caps (after testing with multimeter) from an older XH-543 board I have. I turned it on and saw voltage, but it quickly started plummeting until it hit 0.
How do I troubleshoot this board and figure out the issue? I already bought a new one, so it's not a matter of it not being worth it. I'm fairly new to electronics and would just like to understand the methodology to try and fix this one.
All I've done so far is my own mod, removing the onboard pots (I have 10k pots on the signal input side) and bridging the two pins necessary for it to work.
I was testing it after doing that mod, 600hz sine wave and had audio output, 10.5volts AC across the output leads when my external pots were turned off (they were backwards). I turned it off and flipped around my pots and turned it back on, it was working correctly.
I had set the heat sink ontop of the chip and accidentally knocked the board, I saw a spark on C26, a 1uf cap I believe according to XH-543 diagram, and now I have no output at all.
I replaced it with one of the ceramic 1uf caps (after testing with multimeter) from an older XH-543 board I have. I turned it on and saw voltage, but it quickly started plummeting until it hit 0.
How do I troubleshoot this board and figure out the issue? I already bought a new one, so it's not a matter of it not being worth it. I'm fairly new to electronics and would just like to understand the methodology to try and fix this one.
Additional details. I tested the cap that was on C26, and also removed the cap on C12 and both read .25 nF.
Well shoot, I fixed it. I noticed both 203 resistors on R14 and R18 looked visibly shrunken. I removed them and tested and they were dead. I replaced and the board is working. The only problem is now my pots have barely any range of adjustment for the output voltage. Like 1/16th turn. I'm going to do some of the mods to this board from the above link and then address that.