[agentz]

Ok, weirdness here. Not something I've come across with iBooks before but I'm a bit out of the loop on current issues at the moment, so hopefully someone can shed some light (no pun intended!).

I do Mac support (amongst other things) for a local gov department. One of the things I do is manage the relationship between my organisation and our third party suppliers.

We had a spate of iBooks (G3's and G4's) that have had backlight failures. Fair enough, these things happen.

But out of 5 iBook G4 800's that I've had in the last month with what have looked like backlight failures, two of them have come back with no hardware issues found.

It seems that my 3rd party provider has managed to make the beasties come back to life simply by booting from a CD, then rebooting the machine. And the backlight has come back to life.

I'm very confused by this because traditionally a backlight problem was just that. What the heck could be going on with these machines to make the backlights go dark, nothing that can be done to make the buggers brighten up, but simply booting from a CD is enough to make a difference?

Am I missing something here? Or more to the point, are my guys missing something in the field that they could/should be doing?

[drive-thru]

I had an issue with my iBook where the backlight would go off if I closed the display. A reboot would bring it back. Turned out to be a frayed display cable.
You should mess around with adjusting the screens to different angles to check for this, or you could take the iBooks apart and check the cable to be sure.

Unless it's a software issue (which would be very weird!)

[agentz]

Originally posted by drive-thru:
I had an issue with my iBook where the backlight would go off if I closed the display. A reboot would bring it back. Turned out to be a frayed display cable.
You should mess around with adjusting the screens to different angles to check for this, or you could take the iBooks apart and check the cable to be sure.

Unless it's a software issue (which would be very weird!)

See, thats the thing. The backlights on the machines that have crossed my desk have been to all intents totally dead. No amount of rebooting/moving the screen has resulted in even the slightest flicker of life from the backlight. I just don't get how booting the machine from a CD then rebooting can have any bearing on a u/s backlight.

[drive-thru]

I agree that it's strange, especially if the backlights were dead and not just intermittent. If they work now then I would give them a wiggle and make sure. It's even more strange that there's 2 of them.
Did you try anything before you sent them off? Like resetting p-ram, nvram and pmu? Are you sure it was the backlight, could you still see the image on the pixels?

[agentz]

Originally posted by drive-thru:
I agree that it's strange, especially if the backlights were dead and not just intermittent. If they work now then I would give them a wiggle and make sure. It's even more strange that there's 2 of them.
Did you try anything before you sent them off? Like resetting p-ram, nvram and pmu? Are you sure it was the backlight, could you still see the image on the pixels?

Yeah, one fluke like that I could deal with, but two in a short space of time is a bit weird.

I've given the two machines a fair bit of abuse since they came back to us, the sort of stuff that a typical 6 or 7 year old would/could inflict and never once have the backlights cut out again.

I made sure that the PRAM was reset, followed the power manager reset procedure, and (I think given I couldn't see anything!) used reset-nvram, reset-all in OF.

The display was partially visible if you held the iBook up to a bright light source so it was shining through the Apple logo, typically what you'd expect for a dead backlight.

I'll need to keep my eyes open for another G4 iBook with a u/s backlight and try booting the fecker from a X install disk or something and see what happens.

[Robertk2012]

Ive had the problem when using the spanning hack. Its happened a couple times but I cant remmeber the exact details but it occured when disconnecting the external display.

[agentz]

Originally posted by Robertk2012:
Ive had the problem when using the spanning hack. Its happened a couple times but I cant remmeber the exact details but it occured when disconnecting the external display.

Thats interesting, maybe something worth looking into. I don't think <any> of my users will have been attempting that but it's worth bearing in mind.

[macaddict0001]

when you turn the brightness all the way down the backlight goes off that may well be your problem. there are hotkeys for it on the keyboard by default.