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julianps

macrumors regular
Original poster
Aug 6, 2006
104
16
Wales, UK
I have a early 2008 (Penryn) white c2d/2.1ghz macbook

About 10 days ago, when the cover was put down something kept triggering the optical drive, as if it was wanting to wake-from-sleep, and in the end I opened the cover and restarted it. I was presuming this was an errant application but wasn't sure.

Well three days ago it started turning the backlight off when the machine was in use - there's still data on the screen but the lights are totally off (not brightness=0-like "dim"). I can get the backlight to stay running if either a) i don't let the machine sleep; or b) pass a magnet over the power management daughter-board (by the security hole) which triggers a sleep/wake sequence in which case the b/l comes back on.

I had wondered if this was the inverter but can prove it's not. I'm confident of the backlight and inverter cable as when the b/l works it works fine.

That leaves me with the v2 (UK model number 661-5061 or 992-8243) Energy Star compliant battery cable as the probable cause. This has a daughter-board that apparently contains a Hall Effect trigger for the screen and I'm guessing some other jigger-pokery that it does to drives and screen to ensure ES compliance.

Has anyone ever heard of these battery boards failing and if so is the backlight issue a (or, one of the) known symptom(s)?

Thanks, Jules
 
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