Hi Folks!
So a friend asked me to take a look at a Mac IIsi he had purchased a while back. Unfortunately the board has been damaged by a previous recapping job gone bad. There were multiple missing pads and trace breaks when he brought it to me so I told him I would do my best to try to fix the damage and see if we can't get this old girl going again.
I ended up replacing pads and repairing traces for 11 Capacitors and Resistors in total including:
R12
R13
R33
R43
R44
R45
C20
C22
C31
C34
C37
The via's around C20 and C22 were also destroyed but I was able to route a wire through and connect them on the back to the underside via (NOTE: I am not sure if these should connect anywhere else besides this location as I have no schematic to follow I just have them going to the bottom via atm)
With that work done I tested the power supply that was included and it seemed to be putting out good voltage so I connected it and tried to power on the machine with no Rom Simm and no Memory installed (threw in a battery as well cause why not).
The machine chimed! and then only a grey screen. If I trigger a reboot using keyboard commands the grey screen is sometimes replaced with a yellow and green bar'd screen then a chime...then nothing...
If I add in memory and try to power on I get a chime followed immediately by death chimes.
My friend also gave me a Rominator as he couldn't remember if the IIsi he had came with a Rom Simm or not. The symptoms are the same with or without the Rominator-II in place.
I know the Mac SE/30 has that great matrix for checking trace connectivity is there anything like that for the IIsi by chance?
Is there something in particular anyone can think of that I should look at next? I was thinking about probing around the onboard memory and generally looking for more bad traces; maybe even removing cleaning and re-soldering the memory altogether but that's more just a shot in the dark than anything.
I have access to a multi-meter and an oscilloscope so if anyone has a wave forms and schematics I'm happy to check things but atm I'm playing things by ear here.
Thanks for any assistance!
So a friend asked me to take a look at a Mac IIsi he had purchased a while back. Unfortunately the board has been damaged by a previous recapping job gone bad. There were multiple missing pads and trace breaks when he brought it to me so I told him I would do my best to try to fix the damage and see if we can't get this old girl going again.
I ended up replacing pads and repairing traces for 11 Capacitors and Resistors in total including:
R12
R13
R33
R43
R44
R45
C20
C22
C31
C34
C37
The via's around C20 and C22 were also destroyed but I was able to route a wire through and connect them on the back to the underside via (NOTE: I am not sure if these should connect anywhere else besides this location as I have no schematic to follow I just have them going to the bottom via atm)
With that work done I tested the power supply that was included and it seemed to be putting out good voltage so I connected it and tried to power on the machine with no Rom Simm and no Memory installed (threw in a battery as well cause why not).
The machine chimed! and then only a grey screen. If I trigger a reboot using keyboard commands the grey screen is sometimes replaced with a yellow and green bar'd screen then a chime...then nothing...
If I add in memory and try to power on I get a chime followed immediately by death chimes.
My friend also gave me a Rominator as he couldn't remember if the IIsi he had came with a Rom Simm or not. The symptoms are the same with or without the Rominator-II in place.
I know the Mac SE/30 has that great matrix for checking trace connectivity is there anything like that for the IIsi by chance?
Is there something in particular anyone can think of that I should look at next? I was thinking about probing around the onboard memory and generally looking for more bad traces; maybe even removing cleaning and re-soldering the memory altogether but that's more just a shot in the dark than anything.
I have access to a multi-meter and an oscilloscope so if anyone has a wave forms and schematics I'm happy to check things but atm I'm playing things by ear here.
Thanks for any assistance!
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