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Premium Member
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Discussion Starter · #1 ·
I came home from work today, and tried to wake up my G4, and the light on the power key went out and I smelled burning. :(

After investigating, reseting button on motherboard, etc. - the computer gets power but it refuses to spin up any hard drive (I tried two). After giving up, I schlepped it in to bMac to get fixed. Luckily I have my good ol' iBook, but I miss the G4 already.

Kudos to the girl working in bMac - she knew her stuff and was really courteous. And didn't tell me stupid things like check the cable, etc. - I've heard that at other places before.

Now I keep wondering what is wrong with it - my money's on the processor - I think it's fried.
 

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Mac Guru
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14,627 Posts
Sounds like a logic board wipeout. If the processor was disabled, the hard drive would still spin up. The hard drive spins up whether or not the processor powers up. If the hard drive is connected to a dead logic board, it will NOT spin up. However, unconnected to the logic board, it will spin up as long as it has power going to it. The reason the the HD doesn't spin up when connected to a dead logic board, is because it waits for the signal from the logic board to spin up (the signal is sent to the HD when the G4 is booted) -- if the board is dead, the signal never comes, and therefore the HD doesn't boot up. However, if the HD is unconnected to the logic board, it will spin up because it's NOT waiting for a signal (it realizes it has no ATA cable connected to it) and therefore spins up automactially.

More than anything, my bet is that the logic board is toasted. A burning smell also indicates a logic board malfunction.
 

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Discussion Starter · #3 ·
That makes perfect sense. Thanks for the explanation. Now all I have to do is play the waiting game.
 
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