Had the retro machine I use as a file server make a horrible burning arcing sound, while continue to work perfectly without any sign of smoke.
Now I've just been poking around inside it, with plans to replace the leaking AA batts in the holder with new ones (not PCB mounted btw). It's been playing up earlier which was traced to a suspect ROM socket.
Pull the thing down to get to the motherboard, no sign of exploded tantalum capacitors or anything else that looks burnt. By now I've pulled out everything except the PSU in the process.
oh:
Open up the PSU, no sign of damage anywhere, peering deeper I found a burnt looking resistor on the HV side, which clearly hasn't been arcing. Much later I found fractured (and arced over) solder joints on a mains input cable, 400v cap, and mains filter coil.
I'm going to have to unsolder and redo every single solder joint on the HV side. Naturally the spare PSU I can cannibalise for said resistor is missing, as is the other spare PSU so I have to pull apart a working machine oh:.
Did I mention I really hate switchmode PSUs ? Simple in theory, but electronic Voodoo even when you have a circuit diagram, which parts are the startup circuit for instance ?
Now I've just been poking around inside it, with plans to replace the leaking AA batts in the holder with new ones (not PCB mounted btw). It's been playing up earlier which was traced to a suspect ROM socket.
Pull the thing down to get to the motherboard, no sign of exploded tantalum capacitors or anything else that looks burnt. By now I've pulled out everything except the PSU in the process.
oh:Open up the PSU, no sign of damage anywhere, peering deeper I found a burnt looking resistor on the HV side, which clearly hasn't been arcing. Much later I found fractured (and arced over) solder joints on a mains input cable, 400v cap, and mains filter coil.
I'm going to have to unsolder and redo every single solder joint on the HV side. Naturally the spare PSU I can cannibalise for said resistor is missing, as is the other spare PSU so I have to pull apart a working machine oh:.Did I mention I really
hate switchmode PSUs ? Simple in theory, but electronic Voodoo even when you have a circuit diagram, which parts are the startup circuit for instance ?
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