How to detect and replace a failing logic board capacitor?
I'm struggling with my sister's maccintosh, I'm an IT engineer with some small electrical knowledge...
Failure symptoms are :
- (A) When turning on the computer, everything is normal for 0.5 seconds (all the peripherals are powered), then everything shut down -> The computer does not boot.
- When battery charger is plugged, the computer try to turn on and loop each ~ 3 seconds on symptom (A)
- Every ~ 40 hours, the computer does a successful boot.
- During a successful boot, everything works well, RAM / Disks / etc are OK, Syslog is OK, software is OK
- The logic board have same issue without peripherals plugged in (Disks, RAM, trackpad, keyboard, WiFi etc.)
- Both RAM & optical drive have been replaced 1 month ago for 8 GB RAM & SSD (with compatible units)
- Reset SMC works but does not resolve issue
- The logic board have no sign of grilled components
If I send the computer to Apple (after cleaning my hardware changes), they will surely detect a logic board failure and charge me for ~400 USD to replace it.
I want to repair the logic board, not buy a new one. I think this mess is coming from a capacitor that have some issue to full charge. IMO, that would explain the ~40 hours to wait for a successful boot.
- Could my conclusion be correct ? (Capacitor failure)
- How can I check which capacitor is failing ?
- Can I try to replace it ? (I love to repair 'hard stuff' like this)
- Did you have some nice gifts for Christmas ?
Thanks for reading, sorry for bad english (not my primary language) and happy holidays (if you have some)
Is this a good question?