Mini-Me kit: LM358 overheating

[Anonymous]

When given power, the LM358 overheats quick and gets to the point where touching it for a few seconds is too much. The pedal gets sound when engaged and some effect (I haven’t dialed in the trimmer yet). Only issue I’ve had is the volume when engaged being slightly lower than bypass. It looks like everything is wired up right and the only reason I’d think this is happening is because I had two of the other ICs backwards originally but flipped them. I’m at a loss here.

[mybud]

Please post clear pictures of both sides of the board for starters.

[Anonymous]

These are older pictures, I’ve since oriented c15 the correct way, changed the B100k to the correct B10K and fixed off board wiring, but this issue was from the beginning and throughout all of this. Sorry if they aren’t great I can’t take new ones at the moment. Thanks for any help!

[mybud]

If you have a DMM, the next logical step would be to provide voltages. Connect the black terminal to any ground point and use the other (red) terminal to check DC voltages on the ICs and transistors. Also worth checking that these are firmly seated in their sockets. No offence intended but a couple of solder points look worth reflowing but let’s get an idea of the current voltage readings to begin with.

[Billy]

As mybud says voltages will give us an idea of what’s going on

ICs etc heating up can mean you have a dead short somewhere ie power connected directly to ground drawing excessive current

Without powering the circuit check that none of the LM358 pins have continuity with the IC both in and out of socket

Did you fix your in and out jack wiring from your initial reditt post

Depending on how long you had it powered with your previous faults you may have damaged the LM358

[mybud]

The two flipped ICs may (or may not) have been damaged, as Billy says. If none of the pins are showing continuity (indicating a short), that’s a plausible reason for the 358 overheating.

[Author]

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