JL Audio 1000/1 no mono outout

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I have a JL Audio 1000/1 that has evidence of some moisture damage. (corrosion on the bottom of break out board above the speaker wire terminals) When the RCA inputs are connected there is no output but a screeching noise (Power light is on.) But when you connect the head unit to the Preamp Output section and set the switch to fullrange it has an output but has a motorboat sound. I am assuming that this is a filter problem since the outputs work. Any suggestions?
 
The green in the via and damaged traces like the examples are what you're looking for. These are extremely small so you'll have to look carefully.
 

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If that via isn't open, it will open soon. You need to make a reliable connection from one side of the board to the other. The easiest is to simply use a jumper wire around the back edge of the board. A better way is to drill the via with a #80 drill bit and insert a jumper wire, soldering it to bare copper on each side of the board. If you're going to use a #80 drill bit, buy extras and expect to break several before you realize how fragile they are.
 
There are a few via's in this area. Am wondering what the IC's on top are for and if there is possibly a shorted one due to the moisture. The board seems to have a good coat of con formal coating on it. The transistors check ok, resistors are within tolerance, in this part.
 
Sorry It took me so long to reply with a big thank you. You are the man Perry, it worked fine after I drilled and jumpered about 25 Via’s.. Was a lot of green corrosion coming out of them and I got a mini Microscope with a light then I could see the opened traces that had corroded on the via's.

Thank you Perry
 
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