[SOLVED] PC not booting, fans twitching?

[BurlingtonITGuy.com]

I've got a customer who brought in a desktop, when you power it on the fans run at max speed, no beeps, nothing on the screen, no indication of it getting to POST.

So far I've:

- Removed/swapped RAM
- Removed all cards from PCI/AGP slots
- Tried a different power supply, with this one the computer would only power if I HELD the power button, as soon as I let go, the pc went dead. I tried a 2nd different power supply, it would power on, but the cpu fan would twitch, like it was trying to start, but didn't have enough juice (the PSU was more then enough).
- Tried one of those PCI testing boards that are suppose to show the error codes of the mobo, it just displays --- the whole time

The only thing I can think of is that it's a bad motherboard, but I wanted to get some other opinions.

Thanks!

 

[MobileTechie]

Like you think - it's very likely to be the mobo.

Given that CPUs rarely fail, once you've swapped the other major components around, there isn't much else it can be.

 

[iisjman07]

Very significant chance of a bad motherboard.

 

[Gary Orner]

I have seen this very thing. Everything is pointing towards MB

 

[BurlingtonITGuy.com]

Thanks everyone! That makes me feel even more confident that the Technibble community feels the same

I'll let the customer know.

 

[Cambridge PC Support]

Yep, looks like the motherboard.

But, as a last shot I'd clear the CMOS settings and make sure that the battery is OK.

 

[Knightsman]

def bad mobo.










.........................................

 

[atombytes]

Yes it is motherboard,

if you have some experience with soldering
you can check if there are any bulked or leaking capacitors.
They are pretty cheap and easy to replace, and I myself
many times saved alot of motherboards doing that.

In your case you have nothing to lose, even if you screw up
with soldering

___________________________________________________
Atom Bytes Computer Service
Atom Bytes Servis Racunara Beograd

 

[BurlingtonITGuy.com]

I actually did check the capacitors when I was checking it out and couldn't find anything

I've ordered a new motherboard (only $70 after taxes/shipping), should get here mid next week, I'm sure that's it

 

[atombytes]

I actually did check the capacitors when I was checking it out and couldn't find anything

I've ordered a new motherboard (only $70 after taxes/shipping), should get here mid next week, I'm sure that's it

Well if it is not capacitors than it can only be
north/south bridge.
You ordered new mainboard but still here is some tip
that i use. You can try to save motherboard by removing heatsink
from north and south bridge and with hot air blower you need to heat
up chip to 200 degrees C and keep it up 2-3 min.
You can also "cook" whole Motherboard in owen on 200 degrees C for 5-6 min.
in 50% cases they worked after that.
But cons of this operation is that lifetime of motherboard is reduced and
it can work after that operation as little as 1 month before final total
failure. But also it can serve another year or two so it is worth a try

____________________________________________________
Atom Bytes - Computer Service in Belgrade
Atom Bytes - Servis Racunara Beograd

 

[BurlingtonITGuy.com]

Thanks for the tip, might give it a try on the motherboard once I've replaced it, nothing to loose

 

[PC-MOT]

I second a check on cmos battery...

 

[BurlingtonITGuy.com]

Well here's an update, I put in a brand new motherboard, and it still just powers on and puts the fans at full blast.

I took out one stick, then both sticks of ram, same result (I did this on the old mobo too).

The only thing that it could now be is the processor...so now I'm stuck with an older new motherboard, and no immediate solution for this customer, not to mention I have to leave for training this Saturday for a week

 

[SuffolkComputers]

Have you tried another case? Could be the power button is sending weird signals to the motherboard. Very intesting problem you have there!

When you say its powering on, I am assuming its POSTing too, correct? Maybe you could fiddle with the power management or fan management settings in the bios.

 

[BurlingtonITGuy.com]

Unfortunately it doesn't POST, I'm thinking it must be the CPU, but there isn't any marking to even give me an idea of what type of CPU it is, it's socket 775, but that's pretty general.

 

[MobileTechie]

There are no numbers or other markings at all on the CPU?

 

[ZenTree]

Have you tried another case? Could be the power button is sending weird signals to the motherboard. Very intesting problem you have there!

When you say its powering on, I am assuming its POSTing too, correct? Maybe you could fiddle with the power management or fan management settings in the bios.

I'd second this, or at least take the motherboard out of the case completely and just short the power pin on the motherboard to remove switch out of the equation.

 

[BurlingtonITGuy.com]

FINALLY!

I did try it without the case as suggested, still no luck. However, I replaced the motherboard, power supply, and removed one of the sticks of ram and SUCCESS it boots!

When I was troubleshooting I only removed one stick of ram at a time with the old motherboard, then with the new motherboard the same thing, I never thought that it would be all three things at once failing causing the issues.

So after all that, it wasn't even the CPU that was dead.

Now to see if the customer wants to pay an additional $20 for the power supply...

 

[SuffolkComputers]

Congrats! Not a better feeling then solving a tough troubleshooting problem