Power Mac G3 blue & white problems with graphic card

Hello,

Try running the following tests:

How to reset the System Management Controller (SMC) on your Mac - Apple Support

Reset NVRAM or PRAM on your Mac - Apple Support

You may need to use more specific power-management 'reset' & know

what to expect of those vintage machines, when you try and do this..

• Resetting the power-management chip in your Mac | theXlab/faqs

http://thexlab.com/faqs/resetpmchip.html

There is a small button in the B&W G3 350/400 tower on logic board

that is the re-set button, for CUDA/PMU. These instructions vanished

from the above page; and used to be an Apple support page on this.

[see: an internet archive of G3 B&W service manual for your perusal]

Press and hold the tiny button, on the chip, less than two seconds.

• Mac Troubleshooting: Power Macintosh G3 450 (Blue & White) and Resetting G3 PMU

https://www.macusersguide.com/photo-gallery/power-macintosh-g3/

{.If this isn't done correctly, you may be faced with replacement of

PMU/CUDA/PRAM 'clock' battery. It eats them fast, w/o a thankyou.}

This article linked from same site as earlier, shows several different resets.

• How to Reset Mac PMU: Simple Steps for Resetting the PRAM, NVRAM and PMU

http://www.macusersguide.com/2009/05/resetting-pram-nvram-pmu/

When I was restoring 12/dozens of old Macs, I bought these wholesale

by box/by the gross; at 50¢ each ~ plus shipping; for 1/2AA 3.6v lithium.

(And then, there were those 'plastic square' 4.5v alkaline pram batteries.)

Been kinda fun. Recollect times: troubleshoot, fix, donate: 500+ old Macs.

Good luck & happy computing!🌞🎣

In case some oxidation is compromising the connection in the slot, you could try removing the graphics card and gently clean the gold-plated pins on both sides with a soft white eraser. Be sure that no rubber shavings are stuck to the pins and then reinstall it.