How to find the case wire pinout arangement for an old MoBo?

December 17, 2006 10:53 AM

What's the spec for the pinouts to the case switches/LEDs on an ATX motherboard?

I have a board form an old HP Pavilion (X)775c that I'm putting into a new case. I took off the old connectors without noting them (thinking that they'd be printed on the board like my new ASUS), but they're not.

In case it helps, I have a note that says it's a "Xenon GLA", socket 478 board, but I haven't been able to find anything online with that name.

Is there any way for me to tell, either for sure or best guess, what the layout is? I would assume that it's the same as the new ASUS board, but they don't have anything close to the same number of pins

The HP site has many boards listed that might be the right one, and none of them detail the pinouts on that section of the board.

It's 2 rows: 4 above 5.

Heck, if you could even tell me what that section of pins is called so I could search for it on http://pinouts.ru or allpinouts.com, that'd be helpful.

posted by Four Flavors to Computers & Internet (7 answers total)

it's called the atx front panel header, front panel header, panel header, etc. often on the board you'll see it labelled something like "panel 1".

basically it is the power switch, reset switch, power led, hdd led, pc speaker audio, possibly sleep/standy led.

so you probably can't hurt much just trying different combinations.

most usually the jumpers are connected parallel to the long axis of the header, i.e. odd numbered pins to odd numbered pins and even to even, e.g.

12
34
56
78
9X
posted by dorian at 11:14 AM on December 17, 2006

Are you sure it's a 775c? HP only has one 775c product, the a775c (not X) which definitely does not use a socket 478 board. Could you post a little more general information about the system?
posted by Ryvar at 11:22 AM on December 17, 2006

Here, HP's guide on finding the model number.
posted by Ryvar at 11:28 AM on December 17, 2006

Response by poster: Actually the (X) was to indicate that I didn't remember the number- I think it's either 7, 8 or 9. I may be mistaken aobut the model # alltogether, other than it certainly ends in a 'c'.
I found a bunch of motherboard info pages for possible motherboards on the HP site, but no ta single one of them had a diagram of the pins that I'm concerned about.

I've found some other mobo specs online that seem to have similar pin configurations (like the one Dorian listed, only with the X on the left), so since it seems that I can't really go wrong, I'm going to try different configurations until I get the right one.
posted by Four Flavors at 3:10 PM on December 17, 2006

When I'm in this situation I usually just examine the mobo for anything that looks like it might conceivably be a model number, and Google it. Usually works.
posted by flabdablet at 4:30 PM on December 17, 2006

You're not going to damage anything by plugging an LED on backwards. With the power supply plugged in, short adjacent pairs of pins until you find the power switch. One down, several to go. Poke around with an LED, both polarities, until you find the solid power light and the flickering drive light. See how easy this is?

When the manufacturer's documentation is crap, improvise. And next time, buy a board with a manual. :)
posted by Myself at 4:46 PM on December 17, 2006

Actually the (X) was to indicate that I didn't remember the number- I think it's either 7, 8 or 9. I may be mistaken aobut the model # alltogether, other than it certainly ends in a 'c'.

Ah. Well, the only thing that fits your suggested model numbers is the Pavilion 8775c, which is a Socket 370 machine, so no dice there, either. Sorry.
posted by Ryvar at 5:34 PM on December 17, 2006