For sugary drinks, you'll need to use a household cleaner like 409 or Fantastik. If it's a small area, brush with a toothbrush and clean up with a paper towel or cotton swab. If the whole board needs to be cleaned, soak with the cleaner, wash with a pressure washer (car wash on low pressure) and dry thoroughly.
You can use air from a compressor but it needs to be free of oil and water (condensation). The canned air is good but not as forceful as an air compressor. Be sure to force all water from under the ICs, capacitors and connectors.
You can use air from a compressor but it needs to be free of oil and water (condensation). The canned air is good but not as forceful as an air compressor. Be sure to force all water from under the ICs, capacitors and connectors.
Well that ought to get me some strange looks huh? Pressure washing a circuit board at the car wash!! Its pretty much the whole board. Looking at the schematic you sent me do you really think those resistors could cause audio output issues?? They are linked into a circuit but end up to a ground.
Ok Perry I washed the board, all I had was Kaboom so it worked ok but would not get it all off. I dont know what they spilled on it but it was some gunky stuff. I took it out to the shop and hit it with some high power brake clean and that removed all of it and quickly blew it off with compressed air from my compressor. The board looks great, but I think I will let it sit next to the stove overnight just to be safe. That will make sure there is no water in the switches and what not. I blew it off for about 5 min until I saw not even a drop of water anywhere or under anything. I will replace the resistors tomorrow and get back to you. Thanks again..................
Hey Perry replaced all the 5.1 ohm resistors from a donor board. The right channel works sweet and sounds great. The left channel however not so good. Both channels bias fine but the left channel sounds muted and a little staticy, but the bias sets fine. Do you think one of the A56 or A06 smd transistors could have failed or been taken out. The resistors that I replaced in this channel were REALLY burned. I didnt find any open traces, and the output fets seem to test ok with my meter but was wondering if I should view their output through the scope? Its a small group of components so it shouldnt be hard to track down the problem....
Any thoughts????
Any thoughts????
Have you checked the operation with the switches and pots in all positions?
If so, drive a sine wave into the amp and set the level so that you have about 20v AC output from each channel. Do this with a speaker connected if the waveform changes with/without a speaker. You'll have to tightly clamp the power transistors to the heatsink if you're going to do this with a speaker load. Post waveforms from each channel. Set the scope so that the waveform deflects ±3 divisions and there are 3-4 cycles displayed.
If so, drive a sine wave into the amp and set the level so that you have about 20v AC output from each channel. Do this with a speaker connected if the waveform changes with/without a speaker. You'll have to tightly clamp the power transistors to the heatsink if you're going to do this with a speaker load. Post waveforms from each channel. Set the scope so that the waveform deflects ±3 divisions and there are 3-4 cycles displayed.
Hello Perry the T-8002 is fixed I found that the trace that runs between the 2 5.1 ohm resistors was broken away from the solder pad where the resistor solders to the board since they run in paralell. Also found a corroded faulty speaker terminal. I stock about 500 of those terminals new because they are always stripped, if you ever need any let me know. Thanks again for all your help......now back to the BD15001
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