[cvk]

I'm experiencing a problem with my 14" iBook (G3 700) that prevents it from booting.

When I turn on the iBook I hear the start-up chime, the hard disk spins up, and the display turns on, but it only flashes briefly and the whole iBook mostly goes off again, except that the keyboard keeps responding to CAPS- and NUMLOCK and my optical mouse gets power just fine from the USB port.

If I unplug the hard disk and cd-rom the display will stay on (either flashing the ?/folder icon or in open firmware if I boot into it) for about 30 seconds before everything shuts off the same way (except for the keyboard and USB).

If I unplug the hard disk, the cd-rom, AND the backlight (but not the LVDS cable) on the display I can boot into open firmware and issue commands successfully for hours straight without the computer failing. I just have to use an LED flashlight to read the screen without the backlight. Still, I can list devices and perform any other function just fine.

I tried doing every kind of PRAM, NVRAM, etc..., clear/reset I could find online, including resetting the PMU, to no effect.

After lots of testing it seems to me that my iBook can't produce enough power to run all the devices. I thought it might be the AC adapter so I bought a new one, but it didn't help. I even checked the new adapter's output voltage and it's producing the correct 24V, so that's not the problem.

I thought maybe the display was malfunctioning and drawing too much current, but I found out that if I unplug the display completely (LVDC and backlight) there's still only enough power to keep the hard drive running for about a minute before the iBook shuts off, so it's not just the display that's ruining things.

Finally, it won't charge the battery (which was working previously) at all no matter how long I leave it in the iBook when it's turned off but plugged in.

Since I get a good image (with and without a backlight) on the LCD I know it's not the flexing-cable problem.

I'm thinking about buying a new DC-in board (where the AC adapter plugs in) on eBay for $80 to see if that's the problem.

Any other ideas about what might be wrong?

Thanks in advance for any suggestions.

[ferg]

It would seem my girlfriend has just begun having a similar issue, did you ever solve it? Unfortunately I am not in the same country so I cannot examine the iBook myself.

[Detrius]

It's highly unlikely that the DC-in board is the cause of the problem. More than likely, your PMU is bailing on you. Unfortunately, this is part of the logic board.

Many of the issues that you mentioned though can also be caused by the video processor popping off the logic board, which is what Apple's iBook Repair Extension Program is all about.

Check with Apple about this.


Hank
Apple Certified Laptop Technician

[ferg]

Yeah, the LoBo prob seems to be the issue and here serial falls within the range, she is getting it fixed at her local dealer.

Thanks