Ibook G4 Shuts off After apple logo screen..HELP!!

[MacNewbie85]

I have an used ibook G4. The problem that I have is that, during start up it gets to the grey screen with the apple logo, the little wheel turns at the bottom for a minute, then it shuts off. I don't have any cds or anything because i bought it second hand. but, I do have a external harddrive that I was using to backup my work and system from the time machine.

I've tried:

Resetting the PRAM
Using the external Harddrive to boot

I'm new to mac so please don't be too hard on me

 

[simsaladimbamba]

Have you tried any of these steps?

Mac doesn't boot

Resolve startup issues and perform disk maintenance with Disk Utility and fsck

Troubleshooting: My computer won't turn on

A flashing question mark appears when you start your Mac​

What about using eBay or CL to look for some RETAIL versions of Mac OS X Tiger or Leopard (which it has to have due to Time Machine)?

Btw, a Time Machine backup is not bootable, and PPC Macs are not bootable via USB, only Firewire, though exceptions exist.

 

[max¥¥]

Do a pmu reset (search on the internet about how to do this, it is different between models)
i had this problem with my iBook G3 and it solved it

 

[MacintoshMaster]

When you hear the chime hold down:


alt command P R