Seeing as how I collect all expired things Apple I came into possession of a “dead” MacBook pro of the generation prior to the new unibody construction. It had suffered the all too common malady that befalls that model of a dead video system on the motherboard. Being so completely out of warranty the owner opted to buy a new one rather than get it fixed. It gathered dust on my shelf here till I decided that I really wanted another machine here to run some monitoring software in the background for things.
The way the problem manifests is that the screen turns on at reboot and you see the grey apple display that usually precedes loading. The aspect ratio is off though, the apple is stretched side to side. If you see that then you know that as soon as the OS is loaded the screen will go dark. You cannot make the internal display nor the external DVI port support a monitor after that.
Being very clever, I thought, I purchased one of the USB/DVI adaptors that advertise Mac driver support. The one I’ve got is as “HIS MultiView II” that I purchased from newegg for just over $50. A small price to pay if it got this machine working again. The display driver worked great on my main machine in testing. Now all I had to do was get the old Mac booted again, which is patently refused to do.
I had discarded the battery for it at some point, most macbooks will boot without a battery but I read other accounts that said it sometimes just wont come to life without a battery. I ordered it a $27 replacement one from eBay.
In the meantime it occurred to me that the motherboard battery might be dead too and that might be while it refused to boot. Removing the motherboard battery on this model isn’t that hard, just have to remove the DVD drive and it’s right under there. I tested it at 2.8v which is low, but not dead. It was old though so I ordered a replacement (not an apple replacement, but just the 2032 liion coin cell with solder tabs. so it only cost $5 not $35 with the apple connector, I will salvage the connector from the old one when it arrives) but being impatient I connected my bench supply to the battery connections to try to power up the macbook with that and see if it would wake up, it refused to boot that way either.
The new main battery arrived and the machine booted right up. Even without the motherboard battery installed. Firstly I booted it into target disk mode, and then setup my wifes older generation unibody mac to boot from it’s drive. that way I could run updates on it, install the drivers for the USB video device and make sure that screen sharing was on so that if it was totally dark and nothing working I could still connect to it and control it.
When that was done I connected the USB device and rebooted it as itself and it all came up fine. And it ALL came up fine, even the internal video. The USb video worked fine too, but the internal was working. Run more updates, reboot, video still working. Install OS update, run all updates, reboot half a dozen times and each time the internal video kept working.
It’s possible it’s just messing with me and at the next reboot the internal video will die again, or it’s possible that not having a motherboard battery does something to it, or it’s possible that the install of the USB video drivers did something to it. But for the moment it’s working and that makes me happy. When the replacement mother board battery arrives I’ll install it and see if things change.
update: half a dozen more restarts later and the internal video continues to work. I’ve updated it to lion and run all the other updates since and it just keeps working.
update again (5/2/12) alas, good things cannot last forever and this morning it refused to wake from sleep. Upon restart it was dark again. However, I plugged in the USB adaptor and that is working fine. It does really work the processor pretty hard though so the fan is blasting at high speed while I watch the stock charts, I’ll need to get it a fan to sit on.