I'm working on a dead 512k that's making a rapid clicking noise when turned on. I took an audio recording and uploaded it here:
https://drive.google.com/file/d/12m4cIr_g4gwdeV6ooGvvR8RU5sfe1Vt7/view?usp=sharing
I get no chime and no video. Probing the 5v and 12v lines going to the logic board, I get varying numbers, all below 0.5V. What could be the culprit? I'd like to minimize the number of orders that I place to save on shipping costs, so I want to identify as many likely culprits beforehand as possible. I've already replaced the R39 thermistor since that measured as an open circuit and just fell apart when I touched it, and I've removed the C33 and C37 filter caps for now since they also looked suspect and I read on another thread that they aren't absolutely needed to for the board to work. I also tested the four diodes in the bridge rectifier and found that they seem to be OK.
https://drive.google.com/file/d/12m4cIr_g4gwdeV6ooGvvR8RU5sfe1Vt7/view?usp=sharing
I get no chime and no video. Probing the 5v and 12v lines going to the logic board, I get varying numbers, all below 0.5V. What could be the culprit? I'd like to minimize the number of orders that I place to save on shipping costs, so I want to identify as many likely culprits beforehand as possible. I've already replaced the R39 thermistor since that measured as an open circuit and just fell apart when I touched it, and I've removed the C33 and C37 filter caps for now since they also looked suspect and I read on another thread that they aren't absolutely needed to for the board to work. I also tested the four diodes in the bridge rectifier and found that they seem to be OK.