Hello, I introduce myself, I'm from Spain and I recently rescued a mac classic for an auction, but I accidentally made a mistake.
Everything was correct, I changed the capacitors for tantanium, and even the hard disk worked well. I bought a bluescsi kit and here to look at a previous model, I mounted the board in the opposite direction, putting 3.3v to the ground.
I thought I had burned the AM50C80AJC, I put a spare of Z53C8003VSG but it still doesn't work. (when connecting the blu scsi with the board upside down, smoke came out of F1 fuse 1 and turned off immediately.)
now I describe what I have discovered, I do not have an oscilloscope to look at signals, nor a thermal camera to see the short.
If I leave the Zilog Z53C8003VSG it stays on the screen with scratches, if I remove it and leave it with nothing, without a chip, the screen stays gray with the mouse on the top left active.
I found shorted capacitors C20, C74, C41 but if I take any of those capacitors out and measure them, it works, I understand that I have a shorted micro but I don't know which one it is.
I'm thinking of making a long molex 14 cable to be able to work better and thus test without having to mount a plate in each change.
"Excuse my English is not my mother tongue"
David
Everything was correct, I changed the capacitors for tantanium, and even the hard disk worked well. I bought a bluescsi kit and here to look at a previous model, I mounted the board in the opposite direction, putting 3.3v to the ground.
I thought I had burned the AM50C80AJC, I put a spare of Z53C8003VSG but it still doesn't work. (when connecting the blu scsi with the board upside down, smoke came out of F1 fuse 1 and turned off immediately.)
now I describe what I have discovered, I do not have an oscilloscope to look at signals, nor a thermal camera to see the short.
If I leave the Zilog Z53C8003VSG it stays on the screen with scratches, if I remove it and leave it with nothing, without a chip, the screen stays gray with the mouse on the top left active.
I found shorted capacitors C20, C74, C41 but if I take any of those capacitors out and measure them, it works, I understand that I have a shorted micro but I don't know which one it is.
I'm thinking of making a long molex 14 cable to be able to work better and thus test without having to mount a plate in each change.
"Excuse my English is not my mother tongue"
David
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