03-05-2007, 02:19 AM #1
No keyboard, no trackpad, no display, stuck in Clamshell Closed
- Member Since
- Mar 05, 2007
- Concord, CA
- 12" Powerbook 867 MHz, currently ailing
867 MHz 12" Aluminum Powerbook (not DVI). I bought a replacement display for it on eBay and followed the instructions in the service source for replacing it (taking everything out of the bottom case, opening the display case, etc.). Went to power the machine back on -- chime, hard disk activity, but no display. I figured this was the result of a display or backlight inverter problem.
Not necessarily so. Connecting an external display, I was able to see the Finder window; however, the keyboard and trackpad stop functioning about a minute after powering up. Connecting an external keyboard and mouse works fine -- I can now use the computer (essentially) as a desktop machine.
Here's the weird part -- in System Profiler, under Hardware -> Power, the Clamshell Closed status reads as Yes. So I suspect that the display, keyboard, and trackpad issues are all related to the fact that the computer thinks the lid is closed -- the keyboard and trackpad might work just until the OS probes the clamshell status, then shut down.
The reed switch is in position and connected to the DC-DC board. There is electrical continuity between each pole of the switch and the corresponding conductor; the switch is open when it is out of the computer (no electrical connection across the switch).
So my questions are thus...
(1) How does the computer determine whether the lid is open? In what state should the reed switch be to tell the higher logic that the lid is open or closed?
(2) Is there any way to suppress probing for lid open-ness? This wouldn't be a permanent fix, but it would let me use the computer as a laptop.
(3) Is there any way to determine (other than by replacing and testing) whether the problem lies with the reed switch or the DC-DC board? (I'm ruling out a logic board problem; I replaced the logic board in this computer for unrelated reasons.) Should the reed switch be open or closed when removed from the computer?
Thank you so much for any help you can offer with this problem. If any more information would be helpful, please let me know.
10-08-2008, 10:08 AM #2
- Member Since
- Oct 08, 2008
There is a magnet underneath the keyboard that triggers something behind the LCD.. if the magnet is missing or the sensor behind the LCD has been jogged loose.. the LCD will stay constantly on..Or off depending where the sensor is (close to the latch which might be magnetic)
it's a simple but effective way of telling the computer when the lid is closed or open..
I too have lost mouse control from the trackpad, when I hook up a external mouse, it cuts in and out... Short circuit in the USB? or logicboard issues?
the onboad keyboard seems to work ok..
I have a re-built 867mhz G4 with 1gig of ram
10-08-2008, 12:28 PM #3
- Member Since
- Jul 06, 2008
- In a van down the river.
- 933 Mhz Powermac Quicksilver,1.5GB RAM, OSX 10.5, Tangerine 300MHz Clamshell, OS 9.2
You'd have to pull most of the powerbook apart but what simonhead said is right, there is a magnet inside of your powerbook, located behind the front-side trim that your hands rest above, that determines whether or not to put your computer to sleep.Yes my name is Jaguar.
No, it is not a joke.
I don't find your "I'm a cheetah." joke funny.
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