I installed Ubuntu 9.10 onto my external hard drive cause it's cool to be able to borrow a friend's laptop and be able to have my entire system. It works on the 2 systems i tested it on: my desktop and my mom's laptop. I had to work on something earlier so i borrowed my friend's netbook. I started it up, chose Ubuntu 9.10.20 and it got to the Ubuntu loading screen with the 3 people holding hands right before user selection then it suddenly went black. Naturally, i freaked out because it wasn't my laptop. I held the power button down and reset the netbook but the screen was still black, it didn't even show the BIOS. I repeated the process without my hard drive, and it was still black without the BIOS showing up. I had to remove the battery, plug it to a power source, and power up to start the netbook up again. Can anyone tell me what happened?
My guess is that the netbook didn't really power off when you held the power button down. When you first pushed the power button, the OS probably started the shutdown process, but may not have completed it (may have been waiting for some program to gracefully shut down). Possibly you didn't hold the power button down long enough or possibly that particular netbook does not do a complete hardware shutdown when holding down the power key. When you pressed the power button again to bring the netbook up, it may have still been trying to go down, only now it didn't have the drive attached that it was booted up from previously, so at that point it could have hung trying to talk to the missing drive.
The best way to be able to help you is to know what type of netbook you had.
Without knowing that, it is really hard to know if it is a bug with the drivers, the hardware or anything else.
A Netbook is nothing different from a normal notebook, some vendors use spezialized hardware with different firmwares on them where drivers go mad.
All in all from what you described, I would just bet that different factors summed up to get this fatal result... is it reproducible?