mobo light on, CPU fan spins briefly, but no power up

Joined
Apr 13, 2006
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6
Hello,

I have a fairly old d915pbl motherboard that I've been using for years. I was using it until I wanted to debug a graphics problem on a different system. I took the graphics card out of the 915 for about an hour. When I returned it the system wouldn't boot. I took out the graphics card and it still wouldn't boot.

The onboard LED lights up (green) and the CPU fan spins for about 1 second. The onboard light stays on, but the front pannel light never goes on.

I was initially worried that the PSU died, so I tried a different PSU on the 915 motherboard and the results were the same. I still felt that I hadn't eliminated the original PSU as the problem so I used the original PSU on a different system and the other system powered up fine, so the PSU is good.

Then I got worried about the front pannel "SW Power" connector so I took another system and set it up next to the 915. I plugged the two-pin "SW Power" cable from the new system into the 915 and attempted to use the new system's power button. This didn't help either. I'm not entirely sure this test was valid, so I tried the "short the power pins" trick and pressed a screwdriver against the two "SW Power" pins, no luck, no power on. I'd like to buy a little power switch to see if that makes a difference, but I'm doubtful.

I'm not sure what to do now other than assume the system is fried and upgrade the mobo/proc. I'm also not sure about the CMOS battery. This could be a problem, but I read that ususally the BIOS will post and then complain about the CMOS battery. I don't know how true that is though.

Any suggestions would be appreciated before I replace the system.

Thanks,

//Rob
 
Odd one. I hate it when stuff like that happens.

I dont know. I would try to clear the cmos (turn off power supply and jumper it for 15 min) and while waiting wiggle all wiring. Then find a real rubber eraser and rub the gold "fingers" on the video card to clean them and carefully seat the video card a couple of times and inspect the area where the card goes into the slot for even contact all down the length of the slot. Maybe not screw it down if that causes the card to not sit level, remove jumper and restore power and see what happens. Likely nothing but worth a shot.
 
I have taken components out and replaced them like you and some times I have to reseed the RAM even if I didn't think I bumped them. Usually with a quick start and immediate shutoff the RAM usually is the problem for me. Hope you can figure it out.
 
About a month ago, my daughter's PC started sounding funny so I opened it up and replaced an intake fan. Plugged everything back in and hit the power button. Nothing. CPU fan went on for a sec as did the case fan. Green mobo power LED lit up so I knew the mobo was getting juice. Thought I had fried the mobo somehow when I reached into case to unplug the fan. I started thinking I'd have to get new mobo and do a new install. I cleared CMOS and installed defaults. Nothing. Luckily, I stopped and analyzed everything I did and realized that I had plugged in both the 3pin and 4pin power plug for the intake fan at the front of the case. Once I unplugged the 3 pin plug, everything worked again.
 
I just had this happen to three motherboards in the past three days. This has been the most frustrating time of the year with my hardware.

I have two full desktops that I use daily, one is on 24/7 for all my internet/music/torrent/trading software. I rely on it a lot. One day I had the urge to add a third monitor to the existing two for 3 monitor action. I tried to enable the onboard video of my Intel G31 chipset board. Well I learned too late that if you enable onboard, you can't use pci-e graphics. Even OEM IBM office machines allow AGP + Onboard usage. So this pissed me off. I don't care about the technical reasons, it sucks you can't use onboard + video card.

I updated the bios, everything went well, booted into windows. I went back into the BIOS to figure out why I couldn't use the onboard at the same time. I thought by using "assign IRQ to VGA" was the issue, but that still didn't do it. Changed one setting that had to do with the onboard video with out much memory to use like 4 to 8MB, and the motherboard failed to POST.

Second desktop PC, a gaming machine, I just wanted to add two sticks of RAM to it. It was an overclocked system so of course it freaked out and didn't even go to the POST screen , more like a rescue reset flash function kicked in. It was weird, never saw this dialog before. I powered the machine off after it was stuck in a reboot loop like that. I pulled all components out of the case. Reset BIOS. Pulled out all RAM, even the video, sound, etc. Just the CPU in place. ANd it still powers on, fans spin, then powers off. In a loop. This is a Gigabyte GA DS3L board. It was running overclocked, stable, for the past two years or so with a Q6600. And adding RAM to the system totally fucked it up. The only way I can get the system board to stay on is if I take out the CPU. Oh... but whats the point without a CPU...

I got the board w/ onboard video to POST and boot up, but now NTDLR is missing on the hard drive :rolleyes:

The fun never stops.

Oh the third board, was a brand new ITX board. It only takes DDR PC 5400 RAM instead of PC6400. I called logic supply and they told me about it... I almost RMA'd the board.

I was so pissed off in the last three days that everything was working fine one day, the next I try to just touch something in the configuration and all hell breaks loose.

My gaming machine is pulled out on the desk, with a different PSU, no ram, no video card, and it still is stuck in power on off loop endlessly. It is the best motherboard I have of the three, and its dead as of now. I'm about to go in a hardware slamming rage.
 
how about bios recover mode, pritty sure with the gigabyte boards holding down f6 while powering causes it to use the backup bios and reflash the main on. read the manual..

also use only 1 stick of ram in slot1 (or zero which ever is the lowest..)

i do know that somg ga boards do not like more than 2 sticks of ram, and if you had to use more to get a complete set of ECC ram..

also using 4 sticks of ram will def overheat the northbridge on that ds3l board....
 
Actually I remember some type of recovery mode, it too was rebooting in a loop. I had to power it off... I had no idea it would automatically attempt to reflash the bios automatically.... I turned the power off when it was doing it for the 6th time in a row... I hope I didn't turn it off during a flash.

Shit.
 
If 4 sticks of ram would overheat the thing, I did put a fan on the heatsink. But even in that case the i7's have been out for a while and the life cycle of the board is drawing nearer so its not the biggest loss on my part. But it still sucks.
 
Every time I've experienced these type of symptoms it's been a power issue. It could be the power supply isn't supplying enough (or too much) voltage, and if the mobo detects anything outside of a quarter volt beyond tolerance it will halt the system to save electrical damage. Most often times it's a short, either in a wire, connector, ground fault to chassis, or improper circuit. Verify that there is nothing shorting the board, then unplug and reseat all power connections, if that doesn't work, take the PSU out and try it in another system and another known working PSU in your current rig. This should give you some more insight to what needs to be replaced, if anything.
 
I pulled the whole board out of the system and stipped out everything from it. I did inspect it for shorts but I can't see anything beyond that. The board is bare bones at this point and I turned it over and didn't see anything unusual. I use two PSU's to test it with too...
 
Every time I've experienced these type of symptoms it's been a power issue. It could be the power supply isn't supplying enough (or too much) voltage, and if the mobo detects anything outside of a quarter volt beyond tolerance it will halt the system to save electrical damage. Most often times it's a short, either in a wire, connector, ground fault to chassis, or improper circuit. Verify that there is nothing shorting the board, then unplug and reseat all power connections, if that doesn't work, take the PSU out and try it in another system and another known working PSU in your current rig. This should give you some more insight to what needs to be replaced, if anything.

I had a problem with this yesterday, as a matter of fact. After trying different PSU's, different RAM, different CPU's, etc, I noticed the motherboard bottom had some pins sticking out too far, causing it to touch the case. I pulled the board from the case, put everything on a piece of cardboard, and plugged in the PSU and power/reset switch headers from an old case I had (so I'd have a working power button). Sure enough, it worked after that. So what I had to end up doing was cutting a piece of cardboard to the size of the motherboard, punch holes where the risers belong, and installing the motherboard with the cardboard between the board and the case. It was kind of a pain, but it insulates the board from the case and keeps it from shorting out now. Try pulling the board from the case and running it like I did. Worth a shot, for sure.
 
The problem for me is that I pulled it out just like you said and different parts to test it out w/ .... and still not working. :( :(

I checked all over for shorts but it looks good to the eye.
 
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