Beige G3 Desktop - Doesn’t Fully Power On and Makes Odd Sound When Power Button Pressed

[tigr10]

Hi all,

My old Beige G3 desktop stopped working recently.

On pressing the power button, it now only does the following:

• PSU spins up
• makes odd sound - like static noise
• green light on front lights up

And that’s it. No screen output and no startup chime

I’ve uploaded a video of the odd sound for reference.

I’ve tried the following steps, but no improvement:

• replaced the battery with a known good one
• disconnected IDE cable from HD and reboot
• disconnected floppy drive cable and reboot
• reseated the ROM DIMM
• reseated the memory
• performed power supply verification tests as detailed in service manual - all are as expected

On inspecting the logic board, I did notice something unexpected - some odd build-up of something around C95 - on the right-hand side. I’ve uploaded some pictures. There is a slight odour to this area - but not a fishy one.





Any idea what this stuff / mess is? Could it be from a leaking capacitor? I’m unsure as I’m new to electronics repair and can’t see an obvious trail from nearest electrolytic capacitor to it.

Could this mess be causing the problem? Do I just clean it up with some isopropyl alcohol or something else? Is this an indication of something which can't be fixed?

Thanks in advance for any help / guidance with this. I hope I can get my G3 back up and running again.

 

[Mk.558]

Get some 99% alcohol and a soft toothbrush and clean up the whole motherboard, both sides. You'll probably go through at least a litre, so pick up 2L.

Recap the power supply and motherboard.

If you hear a breaking glass sound, it's usually a memory problem. Check the memory in something else, like a Pentium III or 4 machine. Memtest86 is very good for that. I'm not sure if that nasty stratchy sound is garbled "breaking glass" or something else: Sad Mac sounds were removed around that time IIRC. Since there's no memory on board, it won't boot without memory.