Help! New computer won't POST

[apeiro]

Hey all,

I recently bought a brand new Shuttle SB81P barebones system off eBay. I put in a Pentium 4 661 (Prescott), some DDR RAM and a SATA hard drive. But the damn thing won't do anything. I turn it on and the fans start up and the LEDs light up, but there's no activity on the monitor and no signs of POST.

Diagnosis? Do you the motherboard is bunk, the CPU, or have I screwed something up?

TIA.

[chrisg22]

First thing I would try is disconnecting all of the devices that are not required for boot. E.G. hard drive, cd drive, floppy drive, sound card, see if it boots then. Could be a power issue as the power supply might not be delivering enough power for the system to boot.

[pmanington]

you sure the monitor works? Have you plugged your monitor cable into the right port?

[ultimate]

Check that the bios jumper is in the correct position on the M/board as if it is in the open position it wont boot up.

[arthurleung]

Check that the bios jumper is in the correct position on the M/board as if it is in the open position it wont boot up.

There are so many jumpers on the board it is not a wise idea to mess with the jumpers. If the BIOS jumper was in the wrong place the board would have been dead already.

Try move the jumper named "Clear CMOS" to 2-3 position from 1-2 for 5 minutes (mains disconnected), then put back to 1-2 position.

Most likely the previous owner was using tighter setting than your CPU/Ram could perform. And he have not switched everything back to auto when he sent it off to you.

[apeiro]

Hey guys,

Thanks for the responses. This SFF case has a FB81 motherboard in it, which is all jumperless. It has a "Clear CMOS" button which I've tried, but to no avail.

I also tried a second monitor, just to be sure. If I turn on the computer with the hard drive connected, both the power and the HD access LED light up and stay lit until I give up and shut it off. If I leave the hard drive unconnected, only the power LED lights up. So I know something is going on in the motherboard.

Also, if I leave the computer running w/o the heatsink for ~20 minutes, I can feel the CPU getting warmer, so I know it's getting some juice. Unfortunately, I don't think this little guy has a PC speaker on him, so I can't hear any bleeps or bloops when it turns on. In the past, I've had motherboards that communicate pre-POST problems in a series of beeps. Kinda wish I had that now. :-/

[ultimate]

Is the 4 pin power connector connected.

[apeiro]

Is the 4 pin power connector connected.

Nope. There are three connectors on this board, ATX1, ATX2 and ATX3 (the 4-pin one). The first two are connected, but the 4-pin is not.

Is that required? I don't know what I'd connect it to.

[apeiro]

The board is here:

eu.shuttle.com/archive/en/prod/mb/600/fb81.jpg

You can see the 4-pin connector (red) in the middle of the board. This is the one that's not connected.

[ultimate]

Hi apeiro, do you mean this 4 pin(red) socket should not be connected or should be and if it should it would most probably solve the problem.

Have you got the manual for this board to verify that it should be connected and if so you should have a spare socket coming out of the power supply for this to connect to the 4 pin red socket can you check this out?

[apeiro]

Hi ultimate, thanks for getting back to me so quickly. I appreciate it.

So you're saying I should be connecting the 4-pin connector to the power supply itself? I had originally thought the 4-pin connector put out power itself for PCI-E cards, but I could be wrong (it's been awhile since I bought/built a new computer).

I also found this link:
web.shuttle.com/share/fae/hq/faq/sff/qa/Shuttle%20XPC%20SB81P.htm

At the very bottom, it talks about the 4-pin connector, and you can see the cable that was provided with the unit. Should I connect the 4-pin connector to the power supply? I'm nervous about blowing up the motherboard if I'm wrong, so I haven't tried yet.

[apeiro]

btw, I'm not actually using a PCI-E card right now, just the onboard video.

[apeiro]

I tried connecting the 4-pin power connector to the PS, but nothing changed.

Back to the drawing board...

[ibrien14]

try running the system without memory abd see if anything happens it should put out a series of beeps.

[ultimate]

I tried connecting the 4-pin power connector to the PS, but nothing changed.

Back to the drawing board...

Have you checked that you have a M/board manual for this computer? as I have done a search but cant find anything relevent.

The 4 pin connector is for a pci- e card so it not relevent as you are using the onboard video

How many connectors coming out from the power supply are actually connected to the M/board as there should be a 20/24 pin power connector and a 4 pin power connector can you confirm this?

[apeiro]

Have you checked that you have a M/board manual for this computer? as I have done a search but cant find anything relevent.

The 4 pin connector is for a pci- e card so it not relevent as you are using the onboard video

How many connectors coming out from the power supply are actually connected to the M/board as there should be a 20/24 pin power connector and a 4 pin power connector can you confirm this?

You can see the motherboard manual here:
http://www.zeroflux.org/static/SB81V10.pdf

There's a full diagram of the board on page 16.

There are two connectors connected to the board. One is a 6-pin ATX connector, the other is an 8-pin ATX connector. You can see them in the diagram on page 16 (ATX1 and ATX2).