Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

  • Congratulations strongm on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!

Manually booting motherboard 2

Status
Not open for further replies.

PockyBum522

Programmer
Jun 10, 2003
239
US
Here's the problem. I have a motherboard that has issues. What happened, if it was set (in the bios) to boot whenever it had power. You plug it in, it boots. I got it to post once, so I know it works.

Here's the frustrating part, when it booted it gave me a message telling me the cmos battery was low, so I took the old one, matched it at radio shack, and put a new one in. This erased the bios settings, which I thought wouldn't be a problem as I could just short the pins on the motherboard to turn it on.

Well, that's not gonna work either. There's a listing on the motherboard telling me which pins to short on which jumper to turn it on, but that doesn't work. I've also tried shorting every pin and the ones next to it and that hasn't worked either. I'm hoping all I need to do is get it booted once and I can change the bios setting to boot whenever power is applied.

Here's a high resolution picture of the motherboard if you need numbers or anything:


By the way, I've tried manually shorting the poweron wire of the power supply to ground while the power supply is plugged in, and while the cpu fan spins, (I assume it's just a trace from +3v or whatever to the fan) the motherboard doesn't turn on.

Any ideas?
 
PockyBum522,
First of all,I would highly recommend cleaning the motherboard of dust with some canned air. Particularly the heatsink/fan and memory slots. Also, the cmos battery doesn't appear to be seated all the way down, though this could be my eyes as well.

The cmos jumper appears to be in the correct position.

When shorting the power switch header you want to use something like a small screw driver blade and not a jumper.
The short needs to be momentarily. Refer to the manual as to which two pins are for the power switch.

When you cleared the cmos, the bios should have reverted back to default settings allowing the system to boot if functioning correctly.

"What happened, if it was set (in the bios) to boot whenever it had power. You plug it in, it boots. I got it to post once, so I know it works."

This setting is probably for powerloss, meaning that if it loses power then you have the options for it to remain off,return to last state and is errelivant to weather it is going to power up when you press the power button if the board is functioning correctly.

This may seem like a dumb question and please take no offense, but you are trying to boot with the ATX power connector plugged into the motherboard and with a known working power supply, the correct and working memory installed and a working display adapter? Right?
 
Power on is pin 6 to 9 (it's hard to read but the other ones are directly across from each other so I'm guessing) Don't short the other pins as some are powered and could cause damage if shorted. As mainegeek says the short is meant to be momentary.
 
I'm going to assume nothing's powered if the board's not on, since the psu isn't on. And yes, this power supply has been tested on another computer. The power on pins are 6 and 8, sorry about the picture, but nothing turns it on there. I've tried all pin combinations. I just checked, the cmos battery is fine.

I've cleaned the board with canned air, and I know the memory is at least good enough to post, since I did it once with this configuration. Do you know what the little set of pins is with the blue jumper? The settings are normal, config, and recovery, and the label reads bios config, so why is there a jumper for bios configuration. It seems it's been in the config position, so maybe I should move that to normal (oops) What does it do though, I'd like to learn.

The video adapter is built onto the board and it's all the same config I used when it succesfully booted before. I've been using s crewdriver and I guess I'll go have another try at it with the bios config jumper set to normal. Please let me know what that jumper's for.
 
UPDATE:

It boots! Yay for christmas coming early.

It must have, although I'm not entirely sure, been the jumper set to the wrong position.

Ah, after configuring the bios it tells me to power down and reinstall the jumper in the normal position.

What does that jumper do? Why would you want a jumper to configure the bios when you can just do it when you power on by pressing (del, f2, etc)
 
It must have been either I was holding the screwdriver on too long, or letting it sit overnight, or the bios jumper, but that you for all your help. The power jumpers function correctly and everything works. Thank you all.
 
Note that I'm still interested in the purpose of the bios jumper if anyone knows.
 
The purpose of a bios jumper is to clear the bios(reset it to factory defaults) however usually best to follow the manual before doing so. Also ALWAYS have the power supply unplugged before clearing.
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top