Dead Mobo?

[Poppa_Meth]

I was on my girlfriend's PC tonight just browsing the internet when suddenly the screen went black and a few seconds later the tower shut down. The power button turns the tower back on but I get no video signal and the fans seem to be running full force without slowing down. I opened it up and cleaned all the dust out but that didn't help at all. I'm thinking it is either the video card, PSU, or motherboard. The board looks to be fully powered with all lights and fans running so I doubt it's the PSU. Also when it won't boot, I can hold down the power button to shut it off, but then pushing the button again results in the power light coming on but nothing else seems powered. Holding the button results in infinite loops of trying to power on but no full shutdown occurs. Maybe it is the PSU.

Any input is appreciated.

[classfour]

What is the machine?

Did you hear any beeps?

Have you checked to see the RAM is seated in it's slots, video card properly seated, all cables seated?

You may have to pull the OS HDD and scan it for a virus (using an interface card) if a virus caused the crash.

Most likely: 1. Video Card, 2. Motherboard

If it's the PSU, you may be able to unplug the power connections from any extra HDDs and burners, and get it to boot.

[Bjs]

Lights on and all fans ... nothing else

Generally a fault with psu

[mikel]

I just had the same symptoms last week. Fans, lights, power button OK...everything else dead.
In my case it was the video card.

[Moontrash]

my trusty ole ECS mb died 3 or 4 weeks ago unfortunately...actually the HD died (cyclic redundancy error) so i decided to just reformat the drive(see how much longer i could get out of the drive) as i had nuthin on it. I loaded xp up, booted into BIOS and it kept saying I had a "MAFTOX"(maxtor) hd lol...a few other odd names popped up so I chalked it up to 4 yrs of running 24/7 and it needed to be put to rest. Poor ole BIOS just couldnt take it anymore...I built the PC in march of 2005 and it ran from the summer of 2006. Not bad for only spenidin $210 on it

[Poppa_Meth]

It was about 3 A.M. when all this occurred so I haven't put a lot of effort into checking it out yet. The machine is one I built myself several years ago. It has a Chaintech nForce 4 Mobo with an Athlon XP 64 CPU. Sapphire Radeon video card, Antect Sonota II case with Antec PSU. My girlfriend says she heard a loud pop about a half hour before this occurred. She thought something fell over in the next room over, but thinking back decided that it could have come from the general area of the PC.

I'm pretty sure this is no virus. I had done Avast and MBAM scans a few days before it occurred with everything coming up clean. I'm going to look at it again today to see if the heatsink fan on the CPU is spinning as well as the other fans. It's plugged to the board and the others are plugged to the PSU directly since it has a built in fan control. Unfortunately there is no onboard video on this thing but I do have an old PCI graphics card I could plug in just to see if I can get the BIOS screen. At this point I can't even get to that. I'll check and reseat everything as well. I may have a spare PSU around here I can test as well so long as it has the correct pinouts. Outside of that I'll have to find the manual for the VNF4 Ultra moco and see if there are any error codes I can check. I did pop the CMOS battery as well and reseat it with no success.

[Poppa_Meth]

Some more info:
1) plugged in the main leads from my own PSU. Everything lights up with fans running just like the original PSU does. I don't think the PSU is the issue.
2) Put in an old PCI graphics card. Still not video.
3) Cleaned and reseated all connections. No good.
4) I noticed that my DVD drive does not seem to get power when I turn the computer on. I can't eject it. When I remove it and plug it into a power adapter it works fine. The HDDs on the other hand feel like they are vibrating even with all fans disconnected. Can the Mobo controller which devices the PSU sends power to?

I've been told the Mobo will not POST without a CPU but it should give an error about no CPU found. In my case the monitor only says No Signal so I'm getting nothing from the Mobo. I'm almost certain the Mobo is at fault. Any additional input?

[Constant Gardener]

Any odd smells, bulging or leaking capacitors, physical stuff like that? The non-operating DVD suggests that something is upsetting power distribution. What happens if you unplug HD and DVD and power up? You could try clearing the CMOS - unplug line cord, remove coin cell on board, then short cell holder terminals together for a few seconds, insert coin cell, and try power-up. (I have rescued boards this way, but not often.)

[redwudz]

The DVD power comes directly from the PS. If the PS is on, the drive should have power.

You didn't answer the question about MB beep codes. Very important. If you don't have a beep speaker, install one.

A few MBs will post without a CPU, but not common. Again, beep codes would tell you a lot.

Check the capacitors around the CPU. The loud pop may have been one of them. Since you seemed to have ruled out the PS and the video card as the problem, it does point to MB failure.

[Poppa_Meth]

No diagnostic lights and no beep codes. I'm still trying to find the manual for this thing to see if there are any codes. I thought there was a speaker hooked to this since I've heard other odd sounds from it with certain programs that want to use the case speaker for some reason. No sounds so far and no diagnostic lights. I don't see or smell anything unusual though their house is full of smokers and tobacco smell is hard to get around and tell for sure.

[Nelson37]

Disconnect all the drives, power and data. test.

Use the other power supply for test. You are saying the DVD drive gives no indication of having power but works on another PSU? Disconnect and remove data cable from mobo.

That DVD drive is an electrical device in the chain. It is doing something strange. ANY TEST made with that drive connected needs to be re-done after it is removed. Do NOT forget to remove the data cable from the mobo. Yes, they can short. A short will make a good mobo look dead. A short will make a good PSU look dead.

You do not need drives to get video. Single RAM chip.

Remove video and/or memory. You should Definitely get a beep code. If not, and the speaker works, all drives and cables disconnected, PSU swapped, CPU is way low odds, that leaves bad mobo.

[Poppa_Meth]

No beep codes even after pulling video an RAM. The speaker must not be working. I did pull the IDE cable the DVD drive is on and suddenly the drive works again. Lights come on and the drive opens, which it would not do before. There is still no love from the Mobo though. Tonight I'll pull all cable off the board and replace them as needed and see what happens. If there is still nothing, then I guess the Mobo is dead.

Then I'll have to decide whether to find another 939 board or rebuild the thing up to date. I hate to put the money into a full rebuild since the majority of the machine will need upgraded, and probably the printer as well. All she uses it for is the internet and MS Office for school. I hate to put money in outdated tech too though not knowing how much longer it will suffice.

[lacywest]

This happened to me ... a month ago ........ A customer brought me a PC I built for him ... he said it would not start.

I plugged it in ... connected cables ... and nothing. I changed the power supply ... [I've got extra ones lying around]

On the Abit AN-M2 mobo ... two led lights ... come on .... a yellow one and a red one. With a Power Supply connected a red led comes on.

When PC is up and running ... the yellow LED is also on ... it was dark with the PWS connected.

I also blew out the inside of the tower too ... with a air compressor hose ... lots of crap blew out.

Well ... I started to smell something ... so I started looking intently inside the tower ... whoa !! ......... a nice red glow was coming from a top right corner ........ [I then shined a flashlight inside to take a look].

I could see a small IC Chip ... about the size of your little pinky finger nail ... very very small ... with a round dot about the size of this "o" was brownish white in color ... and in the dark ... it was glowing red in color.

I changed / replaced the Abit AN-M2 mobo with another one [I have extra ones] ... and all is well again.

Why did this happen ...... hmmm ... because it did ?? Or ... they [the IC chip leads] somehow got contaminated from crap inside of the tower and something allowed the IC chip leads to cause a short or something.

Or my blowing out the inside of the tower with the air compressor nozzle ... allowed the dust and crap to short out the leads around that IC chip. Or it was time for that IC chip to go ... see ya ... I am done ... bye bye.

I use this mobo in my PC and it is going on about 2 years steady. The power supply came from a ACER AST180 and I thought maybe it was bad but nope ... I put it back in again and they've got their PC back. No complaints. They even gave me ... $25 bucks for fixing it.

And I was the one who build it for them. I normally tell my customers ... you get a life time warranty ... as long as I'm alive ... LOL.

So ... in regards to your problem ........ could be the Power supply ... or the mother board ... maybe the video card ... maybe the memory sticks ....... with my problem ..... pretty easy to figure it out ... the smell of the chip burning up was the first clue.

P.S. ... Back in my Air Force days .... I refueled jets ... F-111s ... F-100s ... T-33s ... F-4s ... being on the night shift ... we also ... every so often ..... did spark checks.

We ... started up our trucks ... popped the hood and in the dark ... looked for any sparks jumping around inside around the engine ...... definitely dont want to start a Jet fuel fire. And believe me .... I've seen alot of jet fuel get spilled on the run way ... while refueling a jet.

A T-33s ... they are refueled with a nozzle ... the same way you put fuel in your car.

F-111s ... were refueled with a single point nozzle that attached to the left side of the body of the fuselage.

On one particular night ... things didn't go smoothly ... we were on it's right side ... to do a ... De-Fuel of this F-111 ... I will never forget that night ... when the hose became detached from the Single Point Nozzle ... oh crap ... fuel started pouring out the jet to the cement ground.

Me and the crew chiefs ... we all took off running ... one brave person ... went back and flipped the poppet valve handle on the Single Point Nozzle that was still attached to the fuselage. The fuel stopped pouring out. We then called the Fire station and a Fire Truck came and washed down the area.

What was really messed up ... to do a De-Fuel of a F-111 ... a crew chief has to be in the cockpit of the aircraft to flip switches to open and close the tanks on the plane. He was not to happy when the crew chief on the ground told him what was happening. The crew chief has a communication cable attached to the aircraft and is in direct communication with the guy in the cockpit.

Also for a de-fuel operation ... it is part of the protocol ... to a have a guy standing by ... next to the fire extinguisher ..... but in a regular ... refuel ... NO ... not needed.

What caused the accident ?? ... do a reply and I will tell you ... as they say ... haste makes waste ... and that particular case ... haste ... almost caused a big accident ... thank god ... nobody got hurt.

[Poppa_Meth]

Here is a list of new components I'm looking at. Can anyone recommend some RAM. I'm having issues finding a good RAM chip. A lot of them seem to have trouble with i3 CPUs for some reason.

[Poppa_Meth]

I don't see any blown capacitors. I did find the on board speaker so it is definitely there, but no beeps have occurred. Tonight I pulled all IDE and SATA cables and disconnected everything from the PSU except the 24 pin and the 4 pin to the mobo. Still nothing. Not sure what else to try so I'm working on putting together a new system. Doesn't look like there is much I can save out of this one.