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-   -   atypical booting problem - PMU/PRAM reset no good, won't boot off disc, no screen (http://www.mac-forums.com/forums/apple-notebooks/34223-atypical-booting-problem-pmu-pram-reset-no-good-wont-boot-off-disc-no-screen.html)

novoproto 05-04-2006 08:21 PM

atypical booting problem - PMU/PRAM reset no good, won't boot off disc, no screen
 
12" PB, 1GHz, 512MB RAM, OSX.3

my computer isn't starting up or even trying to boot and none of the standard resets seem to help. i do not think it the the HDD, rather, i think it is the power management unit:

i have tried resetting the pram (multiple times), resetting the pmu (multiple times), and tried booting off the system disc but it doesn't even try. in fact, if i do a PRAM reset, i don't get a nice mac "gong" but an annoying "beeeeeeeeeeeeeeeeeeeeep" and a rapidly flashing sleep light. what does THAT mean!?!

i have had a couple episodes in the past where my computer was very stubborn to wake up - or it was stubborn in that it didn't go to sleep all the way. i would close the lid and the screen would turn off (most of these times) but the HD and cpu were still cranking away. i would return in a couple hours to find my computer smoking hot because i left it on my bed (insulation).

now when i attempt to turn it on, it goes through a standard hardware check; where the disc drive and HDD give a quick whir, and the startup chime dongs, but the screen doesn't come on and the cooling fan blasts like crazy - which is wrong because the computer is ice cold. and the HDD and disc drives are conspicuously silent (after the mac chime).

HDD usually give different kinds of signals - and usually time. i don't think my hdd is even getting signals to boot.

i thought maybe the PRAM battery needs to be replaced but then i read on apples website that all ibook G4s and 12" powerbooks don't have batteries, rather a capacitor that can keep the clock going for 20 seconds. i have unplugged it and pulled the battery for a couple hours in effort to drain the capacitor and any other power storage device, but that didn't work either.

i also read that the 12" powerbook is unique from the 15" PB in that it doesn't have a separate PMU board, rather everything is on the logic board (analogous to mother board).

i am about to look for used replacement logic boards (i am attached to this old horse), but before i do are there any other key combination, clever resets that i can try?

thank you in advance

fyrman22 05-04-2006 10:03 PM

Sounds like your logic board. The same exact thing happened to my iBook yesterday. I took it to the Apple store and they said it was my logic board. They said for laptops it would cost between 290 to 320 dollars to fix. For parts and labor. I looked around for myself and the cheapest one I found was 400 bucks for my iBook. Looks like I'l be takin mine to apple. Good luck.....

novoproto 05-05-2006 01:23 AM

Quote:

Originally Posted by fyrman22
Sounds like your logic board. The same exact thing happened to my iBook yesterday. I took it to the Apple store and they said it was my logic board. They said for laptops it would cost between 290 to 320 dollars to fix. For parts and labor. I looked around for myself and the cheapest one I found was 400 bucks for my iBook. Looks like I'l be takin mine to apple. Good luck.....

thank you. that is what i was afraid of. that is a lot cheaper repair than i thought. i was looking at logic boards for ~$700. it sounds like it is worth speaking with the apple people. should i call them (i am out of warranty) or should i just make an appointment at the genius bar?


as a last resort - can anyone add any other options to try (that are cheaper)?

fyrman22 05-05-2006 01:50 AM

I just walked in. I was out of warranty too. Wierd that it was cheaper at Apple than even doing it myself. Mine is goin in tomorrow. I'm having withdrawals already.....


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