A
AnalogApples
Member
Update: I got it plugged in. Mmm that sweet smell of burning resistors! I found a several resistors near my TL074CN chips blackened. The chips were installed backwards. Yikes. So I replaced those resistors and they're no longer burning up. I got to work reseating opamps. Check out how grody these chips are! I cleaned them with a tiny wire brush and reinserted. So far, I have 19 out of the 24 channels working. Seems like these big clunky switches are also dirty inside, as many of the channels crackle to life when i wiggle the switches.
I'm testing voltages going to all the IC chips. So far most of them have 7-8 volts going into them. Not sure what I'm looking for. I'm going to have to learn how to verify if an IC chip is working since theres about 15 per channel, plus 4 per channel in the meter bridge. I contemplated just rechipping the entire board, which I think I may be able to do for about $300. Are IC chips straighforward to test?
Edit: I just ordered an OP-amp testing PCB board from ebay. It has a 12V power supply input, and 8 LEDs for each chip socket, apparently it tells me if it's working, and if the bandwidth is in spec.
I'm testing voltages going to all the IC chips. So far most of them have 7-8 volts going into them. Not sure what I'm looking for. I'm going to have to learn how to verify if an IC chip is working since theres about 15 per channel, plus 4 per channel in the meter bridge. I contemplated just rechipping the entire board, which I think I may be able to do for about $300. Are IC chips straighforward to test?
Edit: I just ordered an OP-amp testing PCB board from ebay. It has a 12V power supply input, and 8 LEDs for each chip socket, apparently it tells me if it's working, and if the bandwidth is in spec.
Last edited:
