CircuitBored
Well-known member
Hi all,
My Performa 5400 is starting to show its age and is exhibiting unstable video at times (normal colours, wavy geometry on the Y-axis). I believe failing electrolytic capacitors on the analogue boards to be the likely culprits as the machine's problem gets worse as it warms up. It is, of course, possible that there's a dodgy transistor or IC at play. A visual inspection has yielded nothing but a capacitor doesn't necessarily have to fail to lose its capacity.
I plan to start pulling caps and checking their values with a 'meter tomorrow - hopefully just one or two are at fault. Sadly there are no schematics, references, or previous repairs recorded online anywhere I can find so this is very much a job that will require me to write down every little thing about every little component as I go. There are some very awkwardly-designed sections on these boards and I will have to desolder large RF shields in order to access every capacitor. Naturally, I will post any discoveries here for posterity.
Has anyone on this forum ever replaced the caps on this particular family of Macs, or even just experienced similar issues? Is there some record of a previous repair out there that has eluded me? If so, please do chime in. Given that this machine has been rock-solid for the entirety of its life until now I suspect that there could simply have been no need for anyone to repair one yet!
Thanks in advance everyone.
My Performa 5400 is starting to show its age and is exhibiting unstable video at times (normal colours, wavy geometry on the Y-axis). I believe failing electrolytic capacitors on the analogue boards to be the likely culprits as the machine's problem gets worse as it warms up. It is, of course, possible that there's a dodgy transistor or IC at play. A visual inspection has yielded nothing but a capacitor doesn't necessarily have to fail to lose its capacity.
I plan to start pulling caps and checking their values with a 'meter tomorrow - hopefully just one or two are at fault. Sadly there are no schematics, references, or previous repairs recorded online anywhere I can find so this is very much a job that will require me to write down every little thing about every little component as I go. There are some very awkwardly-designed sections on these boards and I will have to desolder large RF shields in order to access every capacitor. Naturally, I will post any discoveries here for posterity.
Has anyone on this forum ever replaced the caps on this particular family of Macs, or even just experienced similar issues? Is there some record of a previous repair out there that has eluded me? If so, please do chime in. Given that this machine has been rock-solid for the entirety of its life until now I suspect that there could simply have been no need for anyone to repair one yet!
Thanks in advance everyone.