telemonster
New member
Hello all,
All I wanted was a IIci. Now I am sitting on 4 of them from friends. One works and is my reference, then 3 are in need of repair. So I'm trying to tackle the dead ones so I can give them back to their respective owners.
My board had no battery damage, really no cap damage just a little in the way of scuzzy pins that tone out fine. I recapped it, and it powers on to a white screen with no chime. Some of the funk around the pins of the chips was around a sound IC, but it was really light funk and not really bad like other systems I've cleaned up.
When I am checking the signal lines with a logic analyzer (will post some screen shots of logic analyzer response from good system) I notice that the ARESET signal line on my non working unit never goes high, but the working unit does. This would explain why it never gets past the white screen. There is a slight audiable "tick" when I hit the reset button on the front.
Besides hitting most of the chips in the system, it seems like ARESET is controlled by the two sound chips. Before I remove the sound ICs... anyone know much about how the reset line works?
I've used the 3rd party schematics and see how it feeds through the sound ICs, but not quite sure how the input side of the sound ICs work to drive the reset line?
Normally after a power on I believe the reset line is brought high after a slight delay (once power is good) then a system would normally proceed to boot.
Or am I way off?
All I wanted was a IIci. Now I am sitting on 4 of them from friends. One works and is my reference, then 3 are in need of repair. So I'm trying to tackle the dead ones so I can give them back to their respective owners.
My board had no battery damage, really no cap damage just a little in the way of scuzzy pins that tone out fine. I recapped it, and it powers on to a white screen with no chime. Some of the funk around the pins of the chips was around a sound IC, but it was really light funk and not really bad like other systems I've cleaned up.
When I am checking the signal lines with a logic analyzer (will post some screen shots of logic analyzer response from good system) I notice that the ARESET signal line on my non working unit never goes high, but the working unit does. This would explain why it never gets past the white screen. There is a slight audiable "tick" when I hit the reset button on the front.
Besides hitting most of the chips in the system, it seems like ARESET is controlled by the two sound chips. Before I remove the sound ICs... anyone know much about how the reset line works?
I've used the 3rd party schematics and see how it feeds through the sound ICs, but not quite sure how the input side of the sound ICs work to drive the reset line?
Normally after a power on I believe the reset line is brought high after a slight delay (once power is good) then a system would normally proceed to boot.
Or am I way off?
