# Powerbook G4 Loading Screen and restart. Please Help, i have literally tried it all



## techieboy (Feb 7, 2008)

I am an apple certifed technician but i have a case that is mindboggling me,

i have a powerbook 4 that POSTS, chimes and start to load on the grey screen and then restarts and does it all over again, tried a PMU and a PRAM reset, tried single, verbose mode and nothing, i also tried open firmware and i get a message saying :

"Boot ROM built on 10/05/05"
followed by the normal jargon,


it works with target mode, i can see the HD from another computer, i can even boot from the leopard disc, i restored the unit with the same issues,
i opened up the unit and reseated the IDE ribbons from the HD to the main board. i am running out of ideas, can someone help me?:4-dontkno:4-dontkno:4-dontkno:4-dontkno:4-dontkno:4-dontkno:4-dontkno:4-dontkno:4-dontkno:4-dontkno


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## sinclair_tm (Mar 11, 2005)

I know that Apple has detailed diag tables for things like this, and as an Apple tech, you should have access to them. But, me as a non-Apple tech, I'd try replacing the hard drive. Boot from an external hard drive. Replace the RAM, and Airport card. If it has an internal PRAM battery, replace that (I know some Powerbooks had them, and some didn't). Replace the IDE cable. Make sure that there aren't any jumpers on the hard drive that are in the wrong spot/missing, ect. At this point, it's just a trial and error trouble shooting thing. If none of the above helps, then it's got to be something like the motherboard, and at that point, it's not worth fixing, unless you manage to score one cheap.


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## shuuhen (Sep 4, 2004)

Have you tried a bootable disc? Either the Mac OS X install discs or a PowerPC version of Linux should work. I'm personally a fan of the Leopard disc (if you have that one), since it gives access to more tools than previous installer discs.


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