[Spleenharvester]

I recently got an old computer off a friend (Socket 7 Cyrix says it all ) and I have a couple of Q's.
-the 12 pin PSU - It's in two pieces (six pins on each), which is meant to be at the top?
-Black wire is the ground wire (G on mobo), right?
-There's a thing from the PSU that screws in to the side of the 3 1/5" floppy, what is it?

Thanks.

[wektech]

Look closely at the (p8,p9) connectors, they should be keyed. The pinout is in this article http://en.wikipedia.org/wiki/Modular_power_supply. These old power supplies connect directly to the power switch, and usually have a dedicated frame ground wire which might be the floppy screw you describe.

[Spleenharvester]

They aren't keyed. Which way round do they go? P8 over P9?

[wektech]

The black leads of the two connectors should be toward each other.

[Spleenharvester]

Is it the same as the wikipedia diagram? The black connectors could theoretically be put in facing each other but the wrong way round.

[bushwhacker]

I used to owns 80486 before, and it uses AT power supply.

try to plug in and power up.

If it won't power up, it is reversed. Unplug and plug in the correct position

There should be the white teeth on both P8 and P9 which it goes in corresponding way.

[Spleenharvester]

It's in, the P9 is on the P8 - is this correct?

[bushwhacker]

Like I said, plug it in, and see if it can power up.

If not, reverse the plugs and try again.

[Spleenharvester]

Ok, but is there any risk of damaging it? also, is the yellow wire on the heatsink and fan the ground wire or the black one? It says 'G' on the board next to the connector so I presume that's where 'ground' goes. I could do with an ID on the board really.

[bushwhacker]

For me, none. but just plug in and check if the fan is running or not

If it starts and stop, it is reversed.
If it starts and running, mean it is on correct plug.

[Rik]

A friend of mine killed his mobo by plugging it in wrong. I have worked on many old pc's in the past, black wires to the middle always worked (unless there was a fault already).

[wektech]

I looked at all my old power supplies (could not readily find a motherboard this old), while p8 and p9 are sometimes keyed and sometimes not, the plugs should only install properly in one direction (so the latch catches). Then following the rule that the black connectors are grouped together, there should only be one way to install it.

[Rik]

My friend managed to get them the wrong way round so it is more than possible to do. I know he got them in properly, it was me that spotted the mistake.

[Spleenharvester]

I think I've got them the right way in, however, I now have another problem. I tested the hard drive in my computer and took it out afterwords. Now whenever I boot up my normal PC without it it comes up with 'found new pci device' and I haven't put a new one in. Anyone know how to solve this? Also, when I look up what it is it comes up with 'VIA to ISA' etc and it's clearly confused because the old pc has ISA, and I think the hdd I took out of it caused this.

EDIT: Doesn't matter, I'll put a new thread in the Windows OS forums.