Thread
I've tried two different logic boards - one which supposedly is definitely working.Do you know if it's an old PRAM battery? Could just be dead. Have you checked out the logic board at all?
There was no PRAM battery installed at all - I have a flat one. Is the battery essential for boot?
"Symptom Charts/Video" - slide/pg. 8: (http://tim.id.au/laptops/apple/legacy/quadra.lc_630.performa_640.pdf)
Symptom: "Screen is completely dark, fan is not running and LED is not lit"
Resolution:
"1) Check all external power connections.
[the relevance of 2 in this case is: is the keyboard for sure good?]
3) Reseat logic board.
4) Unplug 4.5 battery, wait 20 seconds, plug in battery, and restart computer.
5) Verify that monitor has power.
6) Remove expansion card, if present.
7) Replace power supply.
8 ) Replace logic board. Retain customer's SIMMs."
Symptom: "Screen is completely dark, fan is not running and LED is not lit"
Resolution:
"1) Check all external power connections.
[the relevance of 2 in this case is: is the keyboard for sure good?]
3) Reseat logic board.
4) Unplug 4.5 battery, wait 20 seconds, plug in battery, and restart computer.
5) Verify that monitor has power.
6) Remove expansion card, if present.
7) Replace power supply.
8 ) Replace logic board. Retain customer's SIMMs."
Yeah these capacitors a big problem. If it's not the actual capacitor itself causing a main board or a power supply to not work, then it's the goo that leaks out and dribbles all over the place causing all kinds of beautiful side issues including electrolysis, pad rot, trace rot, via rot, I/c leg rot. And actual permanent irreversible damage to ICs form the conductive liquid, shortening various legs. Ic's including Ram chips, sound chips, EGRET, CUDA, even resistor packs and VLSI's .