Where to connect case's power-on button?

slayer69

Distinguished
Aug 17, 2009
3
0
18,510
I bought a used mobo that did not come with a manual and I can not find a manual online for it. It is an Intel 02R4085.

I can't figure out how to connect the case's power button to it. There is a series of pins labeled f_panel2 that are on the right edge of the board as it is installed in the case (right next to the IDE connectors). There is a part of the board labeled f_panel1 on the bottom edge of the board, but that is
just a label with no corresponding pins, there's just some metallic bumps at that label.

The pins labeled f_panel2 form a group of 8 in a single line. There's also another group of pins labeled F_USB right next to it, consisting of one row of four and one row of five, but my superb deductive skills tell me that these pins are for USB only.

There's also a group of pins labeled A_F_PNL (A F = auxillary fan?) down under the PCI expansion area, but I doubt that that's where they would place the power-on connectors.

So I'm fairly sure that I need to connect the power-on wires somwhere in the group of pins labeled f_panel2, but I have no idea which wire goes to which pin.
 
You sound like you're on the right track and f_panel2 is the one to try -- usually, the pins connects something like one of these two diagrams, but on a board that old and with no manual, it's hard to tell for sure:

http://attachments.techguy.org/attachments/119549d1194733619/intel-front-panel-pinout.gif

http://www.intel.com/support/motherboards/desktop/sb/img/fpanel.jpg

The main thing to remember is, they almost never connect crosswise, so you can probably rule that out. So, mentally divide the pinout into quadrants and assume one of them will be the power. Then it's just a matter of narrowing down the possible combinations.

Try plugging in JUST the power switch in different locations until you find the position that lets you turn on the machine. When you find it, leave it plugged, then fill in the other connections one at a time by trial-and-error from there (you can't hurt the machine this way). It should take you a max of nine tries to narrow down all the possible combinations.

If the wires coming from the front panel aren't labeled, you're very unlucky, but you should still be able to figure it out using this method with a little patience. Just label them and use different combinations systematically until you get the power plug on the power pins, then keep going. Eventually, you'll get it.

edit: also, if one of the wires coming from the case has a connector that is three pins wide, that means you can tell right away it's the power LED. That's good because you know right off the bat which one it is, but bad because it won't fit on an 8-pin pinout. When all is said and done, you'll probably have to slice the plastic connector down the center CAREFULLY with an exacto knife. You can split the connector without hurting anything; the center pin of the three-pin sheath is just a plastic filler. Then plug them into the final two remaining pins. Hopefully you won't need to do this, but just in case.
 

slayer69

Distinguished
Aug 17, 2009
3
0
18,510
The wires from the case are clearly labeled, so that is not a problem.

I'm not sure what you mean by "crosswise". If you mean that they don't normally connect by orienting the wires 90 degrees from what your linked diagrams show (that is, the two power-on connectors span two rows rather than being adjacent to each other in the same row), then I'm afraid I did not explain the geometry of f_panel2 properly, as it is a single row of eight consecutive pins. It's not one row of four and another row of four. If it means anything, the F_USB group is configured as one row of four and one row of five, like the diagrams show.

But that's probably moot anyway, as it sounds like trial and error is OK? The error part makes me nervous, because I was afraid that I could fry something if I don't get the connections right. But that won't happen?
 

Crashman

Polypheme
Former Staff


Of course it didn't come with a manual, it's out of an IBM machine. You should try figuring out which IBM service manual to download, or get the case it came out of and trace the wires back to the switches and LEDs.

Edit: I found a description for an IBM PC that uses the board:

http://www-307.ibm.com/pc/support/site.wss/MIGR-43028.html

Happy hunting.
 


Ouch. Eight pins in a row is definitely not the normal configuration for a front panel header these days. But it might actually make it easier to figure out, since it's probably divided 2/2/2/2.

But there really is nothing you can hurt by trying different plugs on different pins with the front panel header. The only outcomes you can get are that the power turns on or it doesn't turn on -- and if it doesn't, nothing happens. If you have the LED plug hooked up to the power pins and the power plug hooked up to the LED pins, you're not activating anything. You're just going from one dead state with no power to an identical dead state with no power.

For that matter, you can use the reset button as the power button and vice versa if you want (in fact, I once had a machine where the power button broke off and I had the reset button hooked up to the power pins for several months. The reset button was the power button on that machine, and it was fine). Basically, in the worst case, you get the LED lights reversed, OMG.

If you're feeling ballsy, you can figure out which are the power pins pretty quickly by shorting pairs of two with a flathead screwdriver. If it turns on, those two are the power pins. But you're probably fine with just trial-and-error.
 

Crashman

Polypheme
Former Staff


I blew an Asus board like that one time when I accidentally touched the ground side of the power button to the 5V side of the speaker connector.
 

obsolete99

Distinguished
Apr 10, 2010
165
0
18,710

Crashman

Polypheme
Former Staff

Wow, at least it looks like the USB header is standard:
http://www.duxcw.com/yabbse/index.php?PHPSESSID=9ac2b7757f72e2b27ecd27ea94db190d&board=3;action=display;threadid=18610;start=0
Normal for pin 5 or 10 is to be a ground for the cable shield that goes to the case, so if your case doesn't ground the shield wire you'll have to figure out a workaround.
 
Now that's an odd setup. I hope it's the same.

Crashman: Just curious -- was the board you blew one that had one of those massive all-in-one headers with about 20 pins for power, speakers and everything together, like this:

http://tech.icrontic.com/draco/images/articles/abit_at7_max2_motherboard_review/moboconnectors.jpg

That's the only setup I can picture where that could happen. (Just asking, because I don't want to be giving out bad advice, but it doesn't seem like it'd be possible to do much damage with a regular 8-9 pin setup that only contains power and LED pins.)
 

shushine4nep2ne

Honorable
Feb 14, 2013
1
0
10,510
OMG. So my computer turned off randomly. Would not boot for a whole day of standard troubleshooting. i had messed with the f_panel2 during this process.replaced the power supply. still wouldnt boot. In the meantime (with a new psu and still no boot) i decided to do the paperclip power test with the og psu. nothing. did it to the new one in the case with only one case fan plugged in. both fans turned on. ok. either my mobo or atleast the 24-pin port (bad soder?) is fried, right? or maybe i screwed up the f_panel2 i thought. followed the diagram you posted (and realised that everything is labled, just REALLy small, lol) plugged in the power switch only. and voila. you sir made my day. actually about six this morning.
 

Petros90

Reputable
Oct 9, 2015
3
0
4,510
Basically it's the group of nine pins on the lower right of the motherboard under the serial ATA connector: the LED on the top row left, the power on the top row right.
Bingo. I'll be more careful next time ...
I had foolishly disconnected the power button pins on my e-machines e4264 - without carefully checking where they came from.
Many thanks to capt_taco and the handy intel diagram. He the Daddy.