Xserve won't start up

We had a similar issue with out G5 Xserve. It was running just fine hosting user accounts as it always does, then BOOM, she went down. Our video was a blank gray screen. Subsequent reboots resulted in the grey Apple logo but no spinning gear animation. We couldn't even boot from CD.

We had an Apple tech come out and he replaced the motherboard, drive backplane and one of the processors. That made things worse...

Eventually he placed all the old parts back into the machine (one by one) and then moved the system to our workbench. It booted the first try. He claims that we had "dirty" power in our server room. We're not so sure and are reluctant to put the Xserve back into production. I personally think it is the Xserve's power supply.

Is this the same thing you saw/see?

I'm having the same problem. Actually, I've been having this problem for the 5th time over 6 months. I rebooted it this time because my firewire devices and cd drive wouldn't respond. After perusing the support site, I found that there is a known problem (artnum 88446) of cd/firewire/usb/pci devices do not respond if you have the xserve locked. Well, my xserver is unlocked and it will not come back. I believe everytime I rebooted, the system was locked. IMO it might be the locking mechanism that is the culprit.

http://docs.info.apple.com/article.html?artnum=88446

I just got this problem DP G4 xServe.
.9TB raid5 (238x4) storage 95% full
Disk got full of SMB logs 54 GB!
machine would not respond to logins,
Timbuktu would load (i use Timbuktu casue it takes only 30% Processor power when running where ARD takes 50% of all processor power when idle which for a DP machien registers as 100%)
but finder crashed and would not relaunch.
Programs bounced for several minutes and would not launch.
restarted machine and video would drop out after video reset with no signal
attached FW800 to another xserve and started in target disk mode cleared Gzupped old logs and rebooted machine.
had to attach APPLE branded keyboard and mouse and keep active to get video to stay on with flashing system folder icon.\evne when booting to CD
Zapped PRAM
Zapped PRAM
Option Key at boot No partitions with a bootable system until cd inserted
Booted AHT (xserve 2.0.1) shipped with the box. Passed quick AND passed extendended
Booted Techtools CD all passed (surface test skipped)
booted OS X server 10.4 CD and ran Disk utility Passed verify and fixed permissions.
"No system" icon at boot
attached FW800 to another xserve and started in target disk mode
system look intact to me
Upgraded system using 10.4 server disk
Said would take 2hr 50 minutes only took 18 minutes no errors (hmmm)
No system Icon again
tried to reinstall OS server 10.4 disks said it could not install I needed to erase drive (OMG!) and reinstall.
reran Disk utilty to look at disk and raid all the disks in the raid set had little locks on them is that anything?
server is unlocked.
...stuck.

Jeroen,

The Xseerve is failing to pass its most basic tests. First thing I would do is reset the PMU.
a) Slipe open the case far enough that you can see the power supply.
b) Using a #2 pencil press the PMU reset button located in the little bit of circuit board visible between the processors and the power supply. The button is about an 1/4" to 1/8" round gray disc.
c) wait about a minute then power up the machine, since the Xserve does not have a speak the boot-beep equivalent is both rows of leds lighting up in sucession, do you see those?

If PMU reset does not clear the problem then you are probably looking at a low level hardware problem like a CPU, motherboard or power supply.
--->Steve