I bought recently a Dell socket423 motherboard, complete with CPU, heatsink, 4xRambus sticks and power supply. The seller sold it "as-is" and didn't know much about it except that it came out of a "working Dell server". It was very cheap, barely over $20 for everything including shipping, so I took it. Based on pictures from the ebay listing I have been able to find that the original system was a Dell Dimension 8100. I was unable to find much documentation for the hardware, such as a repair manual etc.

I have received it today; I haven't tried to power it up because I have some concerns about its safety, related to a VRM and its socket.

I haven't seen this style of VRM on any other motherboards, and haven't been able to find anything about it. It plugs in a short ISA-like connector situated between the CPU socket and the AGP slot. But it looks like the slot is damaged, with one of the fingers missing. The system actually arrived completely disassembled so not like the pictures below (I'm the one that put the memory in, the HS on the CPU with thermal paste of course etc). The slot was already like this when I took it out of the box, with one finger missing. I don't know if it's actually damaged or if that finger is supposed to be absent, but it does have a contact on the corresponding place of the VRM itself. I couldn't find any documentation of the VRM module and find out what that contact is for.

If anyone has any information I'd greatly appreciate it.

(edit) Hm, I've looked at the magnified pictures of the VRM and it looks like the contact corresponding to the missing slot finger isn't actually connected to anything. Maybe I'll just try to power it up and see what happens. My eyesight isn't the greatest but I can't see any connection there. It's the last picture at the bottom of this post, 6th contact from the left.