Why would he need to remove the motherboard from his case?
Do you get the first post screen? Does it detect your drives? Or does it literally freeze after stating the BIOS version, etc?
You need to strip the whole system down to a bare minimum. Disconnect the floppy drive, any CD/DVD drives, additional hard drives, remove any modems, network cards, sound cards, etc. Also, unplug any USB/Firewire devices that you may have plugged in, etc.
Basically, all you need to have set up, is the motherboard (with CPU and RAM seated correctly), the main hard drive, and a graphics card. Make sure you have at least your keyboard plugged in (preferabley a PS2 form keyboard). You don't necessarily need your mouse, but I don't think it would hurt.
Once you have your minimal set-up, power the computer up, and keep pressing DEL to enter your BIOS (or your motherboard's equivalent). Once you're in the BIOS, select the option to load default settings. Save the settings, exit the BIOS and reboot. If your machine still isn't getting past POSTing, then your motherboard may have run its course.
Saying that though, you could, with the help of a friend, use their computer to download an update revision for your BIOS (along with its installation utility), transfer it to a floppy disc and see if flashing the BIOS helps. I will warn you though, this is to be done at your OWN risk. If flashing the BIOS goes wrong, the motherboard will be completely void (unless you have a modern Asus motherboard, and-the-like that allows you to get around this).
I hope you get your problem sorted.