I'm having a problem with my 2008 2.4Ghz Macbook. After doing a fresh install of 10.6.0 with Retail DVD, the MB was working perfectly, absolutely no problems at all. I then ran Software Update and installed all the recommended updates to 10.6.8, and I only noticed in passing that there was a Firmware update to do too. I ran that as well, and, IIRC, it was applied after fully updating to 10.6.8 and after rebooting twice. The MB rebooted, ran the Firmware update (which seemed to complete fine, the progress bar completed), then rebooted. Again, IIRC, after running the Firmware update, and I'm now at 10.6.8, I started a Repair Permissions and left the MB for a while. It was the next day, maybe 15 hours later, when I went back to the MB and it was in Sleep. I pressed a key to wake it and this is when the weirdness started.

The screen was "fuzzy", and what I could see was: the Disk Utility window open on Repair Permissions (which had completed) and several Vertical Segmented Bars, which were filling in from left to right. IIRC, it may have looked a little like when you wake from Deep Sleep (or Hibernate, or whatever it was called). Anyway, before progress was completed, the screen went black. Pressing keys didn't bring the desktop back. I did a forced shutdown, reset the SMC, then rebooted. No startup chime. The Superdrive, hard drive and fans spun up, but the screen remained black. After a few reboots, I got a desktop back, and tried to reinstall from both an external HD and the Retail Snow Leo DVD. Both times, the MB booted to the startup screen: with the external DVD, I held down Option and chose the Snow Leo install; with the DVD, the MB started normally while I held down the C key. The boot started from the HD and the DVD, but after about 30 seconds, with Apple logo and spinning "cog wheel", the screen went black. And seemed to shut down. With the external FW hard drive, the drive made a loud click, its LED went off, then it came back on after a few seconds, as if it had lost all power to it, then the LED lit up when power returned to it from the shut down MB. Anyway, the installs failed. I then attached the 2.4 MB to another MB (2.1) in Target Disk Mode and it booted fine into TDM. It showed up on the 2.1's desktop, I ran Check Disk and it checked out okay. I then looked under Startup Disk and the 2.4's disk was listed there, with 10.6.8. I booted the 2.1 from the 2.4's disk and it booted fine. I ran check Permissions, and a huge list of permissions to repair came out. At this point, I've left things as they are. The 2.1 is booted from the 2.4, the latter used as external HD. I didn't want to go any further, for fear of screwing things up, now that I've got some normality back. Any and all advice on how to proceed now would be HUGELY appreciated. Thanks.

Update:

The 10.6 install completed fine and I was able to set everything up.

But:

1) the Macbook's display remains black, though the external monitor works fine, even at 1920 x 1080.

In system prefs, under Monitor, only the external monitor shows up. No option for mirroring and the MB display isn't listed.

2) suddenly, the trackpad button doesn't work

3) when I was asked to choose a picture for the Macbook, I found that the iSight is not recognized (message: no camera found)

So it looks like a few problems still to sort out, to say the least.

Both the black screen and no iSight camera are weird problems, as they literally came out of the blue.