Ask Max: Low or Dead PRAM Battteries
I am having trouble with a Power Mac G4 starting up: intermittent no start up tone, startup tone but no picture on monitor. This came in with a no start problem. The system belongs to the prayer chain at church.
System is a Power Mac G4 running 10.3.9 OS, with a 400MHz processor, 320 MB of RAM (128 MB card & 3 pcs. 64 MB cards), 120 GB Jacobtor HDD, and a Radeon 9000 Video Card. The battery reads 3.6 VDC.
The system will not start up from the internal DVD ROM drive. I have tried the Apple hardware test CD and the OSX 10.4 software DVD.
I have also, removed the 3 pcs of 64MB DRAM, leaving only the 128 MB card. Same results, no video signal. I have also tried both a CRT (gateway) & a LCD (NEC) monitors, different apple adapters and video cables, same results. I have had it start and complete the process a few times. Any suggestions?
When you say the ™battery reads 3.6 VDC,™ do you mean that that is what a Volt Meter registers when you check the battery outside the computer? A dead PRAM battery or even one that just has low voltage can cause a problem like this. PRAM batteries do not recharge and will die after time, even if the computer is always plugged in. If the battery is not the problem, zapping the PRAM five times in a row at startup can clear bad settings. I suspect, however, that you may need to unplug the computer from all power and remove the PRAM battery. Then press the ™PMU™ reset button next to the battery housing. It looks like a silver square with a dark grey or black dot in the center. Reinstall the PRAM battery and plug the computer back in. Also check to see if the firmware is up-to-date. It should be Power Mac G4 Firmware 4.2.8, so update if needed.