[Ham-Mac] Dead G3 iMac, need help please.

[Peter Hunter]

Hi everyone,

I wonder if anyone can give me any help please? I was given a dead G3  
iMac 266 tray loader the other day, and I have been trying to get it  
working. It would be a handy little computer for the shack. It has 2  
x 128MB sticks of ram fitted.

I have tried everything I can think of to bring it back to life.

The first thing I did was to replace the dead battery with a new and  
unused one (I checked the voltage on it first, and double checked  
that it was in the correct way round). This gave the results of the  
machine trying to start and then stopping again.

I took both 128MB sticks of RAM out and put them back in, one at a  
time, one after the other, into the slot under the processor. No  
change whatsoever. So, unless both sticks of RAM have blown, the ram  
is ok.

I took out the original Quantum 6GB hard drive, and replaced it with  
a known working 4gig drive, still no change.

I tried leaving the hard drive out altogether and booting from CD,  
still no change.

The only way I can get any sort of live from the machine is if I take  
out the unit holding the logic board etc., and refit it, and switch  
on. When I press the on/off button it seems to want to start, the  
light on the button lights up, the power supply kicks in, I get the  
chime 'bong', the light on the button changes colour to (I think)  
orange and then blue or green, and then it switches itself off again.

If I press the on button again nothing happens, no matter what I do  
or how many times I press it or unplug the mains cable. The only way  
I can get it to try starting again is to remove the board unit and  
slot it back in.

By the way, each time I remove the board I hit the cuda button.

So, has anyone any other ideas to try? I am suspecting the power  
supply is faulty, but what do YOU think?

Hope to hear some useful advice.

73 all

Peter, G0GSZ