Miphee wrote on 2021-05-20, 12:03:

I bought this board to test my Xeon CPUs. I have a 650W Dell PSU, DDR2 server RAM and plenty of s603-604 Xeons but I don't have […]
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I bought this board to test my Xeon CPUs. I have a 650W Dell PSU, DDR2 server RAM and plenty of s603-604 Xeons but I don't have the control panel assembly that would fit in the Front connector (next to the white floppy connector).
When I plug the PSU in it starts for a split second then turns off. If I try to start manually on the Front pins it doesn't do anything.
Do I need the control panel to start it up? I have no experience with proprietary Dell server boards.
On standard mainboards shorting the PWBTN pins for a second starts the computer but it doesn't work here.
Anybody have experience with these? The board is a refurb and it's brand new (not my picture).

Not sure you particularly need the button panel, but being a server I'm assuming there's some form of built-in baseboard management system at power on to check a raft of status sensors -

- does your Dell psu have both the 20-pin (12V) & 24-pin power connectors
- the standard non-redundant psu has a sensor for fan failure which might be triggering against your own psu
- most of the motherboard fans have failure sensors, and the 4-pin fan headers seem custom...how are you connecting any fans
- did your board come with the VRM for the secondary cpu...if you're only testing with one cpu, try removing it
- there may be a previously logged error which is preventing power on
- have you checked the coin cell has power

PC Hoarder Patrol wrote on 2021-05-21, 04:36:

- does your Dell psu have both the 20-pin (12V) & 24-pin power connectors - the standard non-redundant psu has a sensor for fan […]
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- does your Dell psu have both the 20-pin (12V) & 24-pin power connectors
- the standard non-redundant psu has a sensor for fan failure which might be triggering against your own psu
- most of the motherboard fans have failure sensors, and the 4-pin fan headers seem custom...how are you connecting any fans
- did your board come with the VRM for the secondary cpu...if you're only testing with one cpu, try removing it
- there may be a previously logged error which is preventing power on
- have you checked the coin cell has power

I tried the basic things.
The PSU is from a Poweredge SC1420 so it fits this board. It's tested and working.
I only use 1 CPU so I don't need the VRM module. The CPU is a Xeon 2000MP (but I tried 3 other Xeon CPUs).
I don't have a fan assambly so I just used a generic heatsink. No fan attached.
I used a single ECC DDR2 RAM module in DIMM1.
I used an S3 PCI VGA.
I replaced the coin cell with a new one (not installed now).
When I plug the PSU in the board starts immediately then shuts off after a split second.
I can't find the pinout for the Front header.

That's about it. I checked the troubleshooting guide but it only mentions error codes when the fan isn't working. The error codes are displayed by 4 LEDs on the control panel that I don't have. That's why I suspect that it controls the failure sensors as well so without the control panel the board doesn't start. It's just a guess though.

Is there 40 pins for the front panel connector ? The only Dell with diag leds and a pinout could find is this one, it may or may not help...

No, it's only 34-pin (cable is p/n J4746 / 0J4746) but can't find a pinout for this specific header layout - problem is Dell use similar 34-pin connectors in other systems which don't match the SC1420 🙁

The small PCB is the control panel (power button + power / hd LEDs) and the large one the I/O panel, which looks to be routing connections only, except for ICs for the diagnostic LED array and USB support components. Only other connector (top left) is the chassis intrusion switch

Thanks for the help but I couldn't get it to start. I still think the problem is a missing component but I don't have a source for those so I have to put this aside for now.

Given that the SC1420 was part of their 'Value' tower server range, I'd expect limited cpu support - looks like it may have been restricted to Noconas (800MHz / 1MB L2) and Irwindales (800MHz / 2MB L2)...did you try any from either of these cpu families?