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Chips G · Jul 21, 2012, 11:12 PM

Strange problem here. I have an old white core duo MacBook that turns on and runs flawlessly when it is held 90 degrees sideways (with the DVD drive facing the ceiling and the MagSafe facing the ground). If I slowly turn it horizontal the screen starts to glitch and the computer completely locks up. Trying to boot while it is sitting horizontally doesn't allow the computer to even get to the chime.
I don't remember any single trauma to the computer that would cause this problem. I have tried switching ram and hard drive, no change. I feel that it has to be a hardware issue - perhaps a loose connection somewhere that gets fixed by gravity when the book is on its side?

Has anyone experienced this issue before or heard of it? Google yielded no results based on my searching. Based on my description and hack solution, does anyone have any recommendations for a permanent fix that would allow me to use my computer in the intended orientation ?

Thanks for your time!

Spheric Harlot · Jul 22, 2012, 12:18 AM

The S-ATA cable that the hard drive is attached to, perhaps?

chipchen · Jul 22, 2012, 01:41 PM

sounds like something on the logic board came loose?

many ibooks had issues where the gpu would loosen over time due to the heat... there were weird ways to get it to work again, holding at a certain angle, etc. Some people put objects in to hold it in place and it seemed to work. Perhaps the contact of something is loose and only touches correctly at that angle.

not sure what you could do... but you could try pressing down gently on parts of the laptop to see if that helps. if it does, you may have to take it all apart just to try a fix for it.

Chips G · Jul 22, 2012, 10:10 PM

Thanks for your time and suggestions. As I am not too technically savvy as to repair the laptop, does anyone have any recommendations as to what to do with it? It works "perfectly" on an angle - is there a market for partially working computers such as mine? It feels like such a shame for a fully working* computer to go to recycling.

P · Jul 23, 2012, 10:43 AM

chipchen's solution makes the most sense. If that is the case, one would likely have to reflow solder it in place. There are examples online of people doing that with toaster ovens, but I would not recommend that, since you can break things all too easily. Since gravity seems to be the thing here, can't you put something on top of the loose chip to push it down and in to full contact when the MB is reassembled.

Waragainstsleep · Jul 23, 2012, 11:55 AM

The iBook GPU issue was almost always solved by applying pressure to the GPU to maintain its connections to the logic board. I have seen many faulted with white MacBooks but never a GPU failure like that one.

The only way to diagnose it is to disassemble and if you aren't much into rebuilding gadgets yourself, complete disassembly of a MacBook is not so much fun. You'd basically want to put it together outside of its case and then wiggle cables to see if you can find one that causes this issue. As a start, you could remove the top case and gently poke the LVDS display cable coming out of the left hinge (IIRC correctly). Get yourself what is known as a black stick or more accurately a nylon probe tool so you don't zap anything (yourself included). You can use this to disconnect the top case once the machine is running, though it is better if you remove the top case entirely and boot the machine by shorting the two solder pads marked PWR. If you can find them.

If you have access to an external display for it, you could just disconnect the LVDS from the logic board and see if it still crashes when you boot it flat.

Chips G · Jul 26, 2012, 09:36 AM

Update: I have taken the MacBook apart. I have removed the DVD drive, disconnected the screen cable from the motherboard, and the problem still exists. It no longer boots while sideways, but it DOES boot succesfully when I am torquing or twisting the case it in a certain fashion:

If I push down from the top of the case at the front right corner of the MacBook (where the HD sits) and push up on the right side of the bottom of the MacBook case 4 inches closer towards the screen (effectively, this action is performed by pickup up the MacBook with on hand at the front right corner of the MacBook with your fingers under the case and your palm on top.

Picking up the computer like this causes considerable flex in the machine which I am guessing is causing whatever connection is missing to be complete - the problem is I am not able to figure out what component is the issue.

Does anyone have any tips on further troubleshooting at this point? I have taken pictures of my progress thus far here: http://www.dropbox.com/gallery/70466545/1/MacBook%20Repair?h=95ce6c

P · Jul 28, 2012, 08:37 AM

First try reseating your RAM. It's unlikely to fix the problem, but it's easy to do, and it might help. If it does not, I think the GPU is the most likely culprit.

Waragainstsleep · Jul 28, 2012, 08:57 AM

Can you get a better shot of the text when it kernel panics? It usually contains clues. If you can't get a better shot, boot it up and grab the panic logs from the console app.

shifuimam · Jul 31, 2012, 06:05 PM

Also - try pulling the hard drive, putting the DVD drive back, and booting off an OS X disk. Alternatively, if you have another Mac handy, boot that one into target disk mode and use your MacBook to boot off that drive.

It seems like there might be a problem with the hard drive or the SATA cable.