[intake]

Our windtunnel DP 867 has been off for three weeks while we were on vacation. It was shutdown normally and has run perfectly for weeks on end with out the need for reboots.

I went to start it up this morning and it beeps at me.

Three beeps, not repeated. The power light (on both the CPU and the 19 Studio) then flashes four times, repeating the flashes every 10 seconds or so.

I have re-seated all the RAM and have tried all my RAM in different configurations. I have removed my Crucial RAM and tried running on the stock 256 chips. Still the same result.

What else to try?

[Mr. Blur]

try re-seating the processor module:
http://docs.info.apple.com/article.html?artnum=95052

[Kenneth]

According the the Apple Service Manual for your specific PowerMac G4;

"Computer beeps three times at startup Three beeps mean that no RAM banks passed memory testing.

1. Replace the DIMMs one at a time and test until all bad DIMMs are replaced with known-good modules.

2. Check that the processor module is properly installed.

3. Replace the processor module.

4. Replace the logic board. "

[intake]

Thanks for the replies. I have a hard time believing that ALL of my RAM went bad over three weeks. I have tried all of the ram sticks in all four slots in all combos. No go.
I have no other machines to test my memory in, and am trying to do all I can before going to the Apple Store and paying their diagnostic fee.

I will try the processor module routine.

Ideas on what might cause this?

[Mac Write]

Try one DIMM at a time in each slot. Are you able to boot to the hardware diagnosis DVD? I think trying each DIMM one at a time in each slot will tell you if it's the RAM or not.

[Big Mac]

You say you've reseated your RAM and tried it in different configurations. You really should test each module at a time, because it is possible for one bad one to prevent the machine from booting at all.

[fulmer]

definitely try each module at a time. I had one go bad on me some years back. Had a 256MB and a 32MB module in a wallstreet powerbook. Was seriously worried that my brand-new 256 was bad. Turned out that the ancient (1998) 32MB chip was the dead one.

[intake]

OK, I went back to start trying what was suggested after giving up earlier this morning.

I had left the computer plugged in and had the Apple supplied DIMM in Slot 1 (closest to processor). I came back hours later and switch the power on.

Surprisingly (and somewhat disturbingly) the chime was heard and it began boot. I powered off, reinserted my crucial DIMM's and powered back on. It came up fine.

I'm a little concerned that it cured itself since it is more than likely that it will do this again at some point in the future. I will run the Apple RAM tests from the diagnostic CD, but I fully expect the RAM to be fine.

The only things that I have changed since this computer was new is:

1 256MB DIMM - Crucial
1 512MB DIMM - Crucial
1 120 GB Maxtor ATA drive
Apple Supplied Power Supply and Fan kit (to reduce fan noise).

Is it possible that the power supply kit could be causing a problem? I did reseat this cable during my troubleshooting process, but it did not appear to make a difference.

Thanks for the ideas guys.

[FlatLyna]

Its a longshot, but maybe your backup battery is dead, so the PRAM on you machine was corrupt or empty. Having the machine on for a short period may have charged it (if a nicad).

Nick

[tooki]

The PRAM battery is a non-rechargeable 3.6V lithium battery. It should last 3-5 years.

tooki

[intake]

Tooki, my thoughts exactly. However, it does appear that something indeed charged up over the few hours it was sitting, even if it was just a capacitor in the PMU or other system. Is there something in the PMU that might function independent of the PRAM battery? I know that if you mess with the PMU switch on the mobo (like press it multiple times) that I will quickly drain a PRAM battery, but I thought that the PRAM battery would keep the PMU and PRAM stable while leaving the computer unplugged for three weeks.

Well, she's been running strong for two days now. All diagnostics show the memory to be good. Hmm. This might just be one of those mac mysteries. Thanks for the suggestions all.