Help me diagnose the prob? Is it my motherboard

pratikumbc

Distinguished
May 29, 2004
5
0
18,510
I have a computer in front of me - it has an Asus A7V266 mobo in it. I can't remember what kind of processor is in it - I built this for a friend a while back.

My friend said the computer was working just fine before but now it wont startup. I replaced the power supply thinking that had blown but now it still wont turn on. I press the power button on the case and the power supply light may flash (its one of those with lights in it) or the heatsink may turn once or twice.

It would make sense that the mobo is shot but I still do see the mobo light on which means its getting some power? I checked the connections and everything is solid. I also think the power and reset connections are okay because it does respond to when I hit the power button?

Any ideas on what the problem is?? I'm gonna say its the mobo but without getting a new one I'd like to ask here first. I also dont think its the processor because at least the heatsink would spin on power right? Just nothing happens.

Thanks.
 

fishmahn

Distinguished
Jul 6, 2004
3,197
0
20,780
First thing to do is go <A HREF="http://forumz.tomshardware.com/hardware/modules.php?name=Forums&file=viewtopic&p=521622#521622" target="_new">here</A>and read the Motherboard FAQ - it covers the common first steps to a motherboard that is not booting up.

Mike.

<font color=blue>Outside of a dog, a book is man's best friend. Inside the dog its too dark to read.
-- Groucho Marx</font color=blue>
 

pratikumbc

Distinguished
May 29, 2004
5
0
18,510
Thanks. I did do that however it is not really applicable here. Right now I hit the power button and just nothing happens. Thats why I was asking of the mobo is friend or just done, what are the symptoms? I mean the light still turns on from the motherboard so is it possible that something like the power switch is bad from the case or anything of that sort? Any diagnosis here would be great before my friend shells out some more money.
 
G

Guest

Guest
just make contact with the two pins where the button is attached.
You just need to make a brief short between these two and the mobo will start (if its a defective button)

With a new PSU with no fan spinning, probably the mother board.
Have you checked for <A HREF="http://www.badcaps.com/" target="_new">bad caps?</A>

Asus P4P800DX, P4C 2.6ghz@3.25ghz, 2X512 OCZ PC4000 3-4-4-8, MSI 6800Ultra stock, 2X30gig Raid0
 

endyen

Splendid
In your shoes, if everything ( especially caps) looked fine, with no bad smell, I would start disconnecting things.
I would start with any pci cards, then drives, then each stick of ram, then graphics, then chip. The last thing you take out before the psu fan spins merrily was the problem.
 

pratikumbc

Distinguished
May 29, 2004
5
0
18,510
Well just an update. I finally got around to playing around with this and received a new mobo (well it was used but the same old mobo version that I had before). Still NO LUCK! I unplugged all my PCI cards and then drives and still the same behaviour. The only two things I have not swapped out are DDR RAM and the processor.

Again, the behaviour is the heatsink fan will spin a few times and the lights will come on the power supply(Its the kind that lights up briefly). I've tried a new PSU and a new mobo now and those still are the same result.

Is this typical of a bad processor or RAM? All my comps have SDRAM unfortunately but Im thinking I can prob. just purchase some at Best Buy and return it if I'd like? Either way, what do you guys think these symptoms are? I was always under the impression that if the processor was bad, still all the fans would turn on from the motherboard. Am I incorrect? Please advise.
 

offgreen

Distinguished
Sep 11, 2005
76
0
18,630
I had that happen to me to. When it came down to it figured it was either the CPU or motherboard. Though your system should make some beeps if the RAM is not in and the CPU works. In my case though I just ended up scraping it all and making an new system figuring what I had was crap.
 

pratik97

Distinguished
Oct 29, 2003
13
0
18,510
Well its me - same as pratikumbc. That wasn't exactly the answer I wanted to hear.

But again, any other ideas? My question would be if the CPU is dead wouldnt the fans still work from the mobo? Really hard for me to diagnose this!
 

endyen

Splendid
The power fan will spin up, if you board is good, even if nothing else is attached. Try that, with the mobo sitting on a piece of cardboard, next to the case. That means no chip, no ram, nothing but the mobo, and the psu, with only the power switch to the case connected. I do mean no drives connected to the psu or mobo as well. If the fan spins up, add the chip and hsf, and try again. Still spinning up? Add the ram. Continue adding things, till the psu fan wont spin up. The last thing you added is your problem.