Powermac 7300 won't start up

Question

Although the on/off light comes on, the monitor stays blank and my Powermac 7300/166 will not start up from hard drive or disc. I'd like to try and repair it, would replacement of the power unit be the place to start?

Answer 1

If your 7300 has sat in storage or has been disconnected from an electrical outlet for an extended period of time (12 months ->), the 2005 battery could easily be fully discharged. I'd recommend that you remove the processor card and check for discoloration of the gold-plated pins along both sides of the card's lower edge. If the processor card's connection is compromised, you'll experience the same symptom that you've described. To clean the pins, use a soft white eraser and gently rub them to restore a bright appearance. Be sure to blow off any rubber shavings, prior to reinstalling the card. You may want to do the same thing with the memory DIMMs, L2 Cache, and VRAM cards. Hopefully, the computer will start up normally. Although I don't usually advise investing $$ in such an old computer, you could probably find a very inexpensive/used G3 processor card for your 7300 at eBay. I equipped one of my 7300-200s with a G3-333 MHz processor card ($10) and it makes a considerable difference in performance. Your 7300-166 (marketed in Europe & Asia) has the slowest processor speed of the 7300 series, as the other models had a 180 MHz or 200 MHz processor card.