Proliant 800 CPU/VRM problem?

[Jelle_1]

Hi everybody,

I have a problem with a Proliant 800 with PII 400 MHz CPU, which used to work fine. When I turn on the power, the fans start, but nothing happens (no POST, nothing on screen). The CD-ROM LED is blinking in +/- 1 sec. intervals.

When I look at the motherboard, both the CPU 1 LEDs (PWR and ERR) are off. I've noticed that the red ERR LED blinks for a very short time when I put the power on and off (but I don't know if this is normal behaviour).

Could this be a problem with the CPU or VRM? I would think it's the VRM, because the PWR LED isn't green, but I don't know if my thoughts are correct.

Thanks in advance.

[JohnWRuffo · Accepted solution]

Jelle:

Open the box and make sure your processor speed switches are set correctly.

1 - On
2 - Off
3 - On
4 - On
5 - Off
6 - Off

Do you get any POST beeps? (long / short)
Does the screen flicker at all when you hit power?

You could be right about a PPM or Processor, but it could also be an unseated card or a weak power supply... or worse yet, the bios chip...

ftp://ftp.compaq.com/pub/supportinformation/techpubs/maintenance_guides/320984-001_rev1_us.pdf

[Jelle_1]

Hello John,

The switches are set correct.
When I hit power, I don't get any beeps and the screen doesn't flicker.

Unfortunately, I don't have another system here to do some CPU switching...

Jelle

[Sunil Jerath]

Hello Jelle,
Please reseat the CPU, RAM, VRM and all the obvious cables or boards in the system. Not only the VRM it could be anything.

Regards,

[JohnWRuffo]

Best bet is to "bench" this box... go down to the bare minimum (only enough RAM to boot, video card and the processor) Remove EVERYTHING else from the box. No HDD, Floppy, PCI cards... nada! Then try to boot. If you get something from it at that stage... add components one by one until the system does not work...

Have you tried installing another video card in the box on the PCI bus?

[Jelle_1]

I have been rather busy and thus not yet been able to try all of the suggested options. I've already tried to remove some components, but this still didn't give the desired effect (still no green CPU PWR led). I will try the suggestions next week, thanks for your cooperation.

[Jelle_1]

I've managed to get another VRM, when I use this new one, the green CPU LED (PWR) is on again. But the system still refuses to boot (still no beep, nothing on screen), even when I strip the system of all PCI cards, storage, etc.).

I also have tried another CPU, when I use this one the system won't boot either.

Anyone have any suggestions about what to do now?

[Jelle_1]

Hmm, it's getting even stranger.
With the new VRM and CPU, I manage to get the Compaq Proliant splash screen (which is shown before you see the info about the processor etc.), but when this screen disappears, the system switches the power off. Some kind of overheating/overpowering protection?

[Sunil Jerath]

Hello Jelle,
Can you please post the part nos you have installed i.e. CPU/VRM in your system. Also do you have any third party Hardware in the system??

Regards,

[Jelle_1]

No third party hardware (I did have a new PCI videocard installed, but I have removed this one since this trouble started).

The CPU is: 400/512/100/2.0V S1
The VRM is: 225431-001

The old CPU was: 80523PY400512PE SL2U6
and the old VRM: 327563-001 (spare number: 327660-001)

As far as I know, all hardware is/was original.