1.25GHZ Imac black screen ( blue at first )

timdab

Registered
Hi all, i'm going to edit this post to simplify it a little in hope I may get an answer :)

G4 imac ( 1.25ghz, 256mb ram, OSX 10.4.3 )

Problem:- . Screen stays black on boot up,( happend after power cut, first boot up after Powercut it stayed blue, this happend twice)

I've Tried:-

Booting from my tiger disk = Black screen
Resetting Pram Iv'e let it chime up to five times = Black screen
Pressing the PMU reset button it made a click noise so I'm pretty sure I pressed it in ok = Black screen
Booting G4 In target mode = Black screen, but the harddrive appears on the target mac
Turning brightness up using F15 = Slightly less black screen

I've noticed:-

Computer chimes on start up & I can hear the HD working
If I press a key after letting ( I think ) the Imac boot up fully, I hear the alert noise you hear if you do somthing wrong on your mac, If I press return ( the only key that doesn't make that noise ) none of the keys make the noise anymore?
Screen does flick from it's completly off black to an on black on startup

Questions:-

Could the Imacs battery need replacing?
Can I do any kind of hardware test on the G4imac while in target mode using my host mac?
Is the screen dead?

Thanks in advance
 
I've got the same bloomin' problem!!! My imac is just 3 years old and I am ready to chuck it out of the window!! When I boot up the screen stays black but it is an intermitent problem as it does come on after persisting, keep turning on and off. I have changed the battery, reset the pram, pressed the pmu button, run disk repair permissions and run a hardware test but nothing comes up as having a problem. I am at my wits end!!

Join the club!!
 
We also have this problem. There is another post on this forum, dated October 14, where someone suggested that the backlight on the LCD was dead. You can diagnose this by restarting and shining a "torch" (or flashlight, I think he meant) during startup. You should see some image.

I'm off to try that and then to call the friendly tech support people to see what can be done.

Do you both leave the computer on a lot? I'm a believer in shutting down every day but my husband, who bought it, thinks computers do better when left on.
 
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