I am a former pioneer repair tech. Bought a avh4200nex with a blank display. Unit powers up but I put a bad display on the unit and shorted out a fuse on the main board. Just need to know the location to check, thx 

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I dont have the test jigs to lay the boards out and take voltages unfortunately. I guess when the monitor or keyboard are corroded it blows a particular thing. Just need to figure that out, thanks