Sorry for what is going to be a long mail, but I want to describe my problem in as much detail as possible.
I was backing up my 15” powerbook to an external, self powered USB external HDD. I'm not sure if it is relevant, but my powerbook was never able to use external USB drives without independent (even the ones that work ok in other powerbooks).
During the backup I got a message saying “"You need to restart your computer. Hold down the Power button for several seconds or press the Restart button."
I did so (and also unplugged the external drive, etc.). While the computer was restarting I got the same message. After a few failed attempts I decided to boot from DVD, as previously I eventually got the same message. I thus assumed it was a hardware problem.
I tried booting in safe mode, resetting the VRAM, the power settings, etc. Nothing appeared to work.
At some stage the computer stopped booting up. I just heard the starting sound but nothing happened afterwards.
I decided to leave it alone for a few hours.
I gave it another shot, to my surprise the computer booted up perfectly!
Everything was working fine except it didn’t recognize the keyboard, mouse or trackpad. So I let the computer running, and used the wireless connection and backed up the entire drive, which took a few hours (probably 10h or so).
The next day I turned it back, this time everything was working perfectly it recognized keyboard, trackpad, I was able to check my e-mail, etc.
I eventually connected my usb mouse to it and I noticed it wasn’t recognizing the mouse (tested it on both usb ports). After a while the computer stopped responding (keyboard, trackpad, etc, everything was, at least apparently, dead).
I tried to reboot it, but it simply wouldn’t boot (as previously just the starting sound). Took it to the shop and they told me that the motherboard needs to be replaced.
In normal circumstances I would believe this diagnosis, but unfortunately computer assistance in Portugal is no exactly reliable (especially with apple computers).
Is there anything I can do to determine if this is really a motherboard problem?
Can it be just a problem with the USB ports?