iBook G4 1.33 Ghz - Boot Problem

craigymusic · #1 March 24th, 2009, 07:30 AM

I was given a 1.33 Ghz 12" iBook. I have been working on it for some time. The start up chime sounds, the usual whirring sound happens and then it either boots normally, or stops at a black screen at that point. It is quite random. I have changed the hard drive, I have tried two different logic boards: it still happens. The only other repair I have done is to repair the display cable. The repair involved finding which wire in the cable (of 4) was broken and soldering a new one in it's place and then re insulating it with tape. When it boots the display is perfect, all the ports work, the screen does not flicker if the lid is moved etc. I have taken out the extra RAM, and just used the built in RAM...it makes no difference. I don't know what to do next.

I should add that there is no video out if the computer stops at the black screen point- I suppose it has not booted up so it has not got to the point of powering up all the ports etc.

I have tried different batteries, and two different power adapters as well. When I say Random I really mean it is Random.

Thanks, in advance!

edadams · #2 March 24th, 2009, 12:58 PM

Hi
When it goes to black screen can you hear the hard drive working or is the machine off? Does the caps lock key light up at this point?
It sounds like a video problem to me, maybe another loose/broken wire?
Ed

craigymusic · #3 March 25th, 2009, 05:52 AM

Yes, I can hear the hard drive revolving, and the caps lock light is working. One strange thing is that if I press number lock (F6 on the iBook) the light is not coming on, but if I press F5 it does...Thanks for your reply.

edadams · #4 March 25th, 2009, 12:39 PM

Hmmm, yes it does sound like a video/lcd problem if the machine is still going after the screen is black. If you hookup a external monitor to video port does it show anything before the 'blackout'? The external video should become live at some point in the boot process.
Ed

ora · #5 March 25th, 2009, 12:41 PM

He already said the video out didn't work.

Quote:

I should add that there is no video out if the computer stops at the black screen point- I suppose it has not booted up so it has not got to the point of powering up all the ports etc.

edadams · #6 March 25th, 2009, 12:54 PM

Ora, I asked if there was video before the blackout, not after.

craigymusic · #7 March 25th, 2009, 04:19 PM

Hi, folks. The iBook boots fine sometimes, with everything working. Othertimes it starts to boot but does not go beyond the black screen- with nothing working. I can hear the drive spinning, but that's it.

edadams · #8 March 25th, 2009, 07:22 PM

My guess would be a video or loose connection issue if the machine still responds when screen is black.
If you have another mac handy, you can turn on one of the file/vnc sharing options to see if its available on network while black screen.

Oh and greetings from across the ditch

Ed

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