I need assistance troubleshooting this Korean amplifier that runs on LM319 and two 74HC02. It's not producing low side drive,it powers up for like 1 second and I get a DC spike on the low side drive before the amp goes into protection.
You need to learn to use datasheetdatacatalog.com for datasheets. The LM319 is a comparator with an open collector logic output, yes or no. The 74HC02 is a quad nor gate with dual input, also with a logic output. the 6N137 in the foreground are opto-isolators. The 78M05 in the foreground are voltage regulators. The 4560 is an actual linear op amp, but not one with enough drive to power a speaker. If this device has a speaker, or a phone jack suitable for a speaker, you need to trace back to an IC with a heat sink. Terminals & PC's have low power 2 to 4 watt IC's for powering the speaker or headphone. Happy hunting.
6N137 optos, logic ICs and 319 comparators are often used in class D solutions, but I don’t see any hexfet switches in that pic. Perhaps the camera is not pointing at the right place.
As a side note... this looks to be a CAR Audio amplifier, so should've been posted in the Car Audio section where he'll get a far better response.
Telling people the brand and model of amp will also be of relevant use to those thinking of helping him.
Telling people the brand and model of amp will also be of relevant use to those thinking of helping him.