Need Help with iMac 350 - Won't boot - keyboard or mouse not working!

Question

Hello,
I've scoured the web looking for answers, and can't find any, so maybe someone here would be kind enough to help. I'm working on an imac 350 blueberry for my sister and I'm having all sorts of trouble.
She bought it last week, it started up (8.6 os) no problem. Powered up and down a few times, then all of a sudden, it won't boot. I'm currently getting blinking folder/happymac/question mark when trying to start up.
Here's the big problem - the keyboard and mouse do not work now. I've tried three different mice and three keyboards and no dice with any of them. I have the 8.6 CD from her previous imac (bondi), and I can hear it spinning, but there is no way to start up from cd.
I've also tried 2 other hard drives with the same results.
Tried resetting CUDA on logic board, taking out battery, no change. Bought new battery- no change.
I would love to at least get the keyboard working to see if I can even startup from cd, anyone have any clues on how to get it working? The strange thing is that the keyboard has a power on button, and it works to start the thing up, but dies when it tries to boot. Sometimes I just get a grey screen with the pointer icon, and I can move the pointer with the mouse for a second or two, then no response.
I appreciate any help or suggestions on locating the issues!
Thank you!

Answer 1

When I said "but dies when it tries to boot" and "..then no response." I meant that the keyboard works to power up the computer, but won't work for anything else. So, I am figuring that the usb ports are supplying power to the keyboard and mouse, but the usb ports aren't relaying information from the keyboard or mouse.
How do you know the mouse isn't working? Won't you have to wait until later in the boot to tell?
The poweron key is a special case. I think that it works by lowering/changing the voltage on one of the usb cables. I read about this somewhere. Anyway, this function was eliminated from later usb keyboards and macs. Maybe a working power button doesn't mean what you think.
I would love to boot into open firmware
Could you try powering up from the machine? Is there a power button on the lower right of the machine?
Have you tried this key combo?
commandoption+of
The letters are in lower case. Hold all down then poweron the machine. I'd poweron from the machine as apposed to the keyboard.
You could try another usb keyboard.
We actually did boot up the computer several times with it upside down. Not for any reason, except it's become a real PIA to flip it over every two minutes to start it, then take it apart and boot again. When booting either upside down or right side up it shows the same thing - blinking folder w/finder icon and question mark.
Yes, I agree. You could try removing the clear plastic around the bottom of the machine. At least you will not have to slide in the carriage. Note. The tv portion will still be surrounded by plastic! Don't remove the plastic around the tv!
Hope I am not interfering with Richard and his comments.
Richard: Is this the orginal keyboard? When did Apple get rid of the poweron key from the keyboard? My iMac 600 didn't have the key and my iMac 233 does.
Robert
Robert