New system power up probs (A7N8X deluxe)

[PhilM]

Hi everyone
A mate's son has just built his first PC and it's a pretty potent box -
trouble is, it won't boot up so he's asked me to have a look at it!
I've got a feeling it's a dodgy mobo but I could be wrong, just wondering
if you could give another possibility that it could be!

Basically, it's an Athlon 2600 (I think) in an Asus A7N8X deluxe mobo, 1
gig ram and a Radeon 9700...

Right, when I powered it up, everything sprang into life for 2-3 secs
(nothing on the monitor though - plus no beeps or anything) then just died
and switched itself off.
The same thing happens every time - though once it did stay powered up
somehow but there was nothing on the monitor - just a blank black screen!

Initial suspects for me were an underpowered PSU but it's a QTec 450W-er, I
disconnected the DVD and CDRW and put a 32mb AGP graphics card in but still
got the same thing.

Then I thought there might be a thermal protection built into the board and
he hasn't fitted the CPU correctly - possible maybe???

There seems to be a lot of experience with this board here - it's been 2-3
yrs since I last built my PC and I'm a tad green with the latest mobo
technology.

Any suggestions would be very welcome

TIA

 

[alan buckley]

Have you tried removing the battery and draining cmos via cmos jumper?

 

[Nils Gunnar Ström]

I noticed the same problem about half a year ago. A friend of mine had
also built a new computer which after power on just turned off again
after 3-5 secs.
That was because he had not mounted the heatsink correct on the
processor die and therefore the mobos thermal protection circuit shut
it off.
So my suggestion is that you demount the CPU and heastsink, carefully
clean the die and heatsink, apply new thermal grease and mount it back
again.
/Nisse

 

[Ron]

Hmm. Also, isn't there a requirement for a fan to be attached to the CPU
fan header? (i.e.: no fan RPM wire attached = no hsf presumed by mobo?)

Just thinkin'.
Ron
(Let us know, please.)

 

[PhilM]

Hmm. Also, isn't there a requirement for a fan to be attached to the CPU
fan header? (i.e.: no fan RPM wire attached = no hsf presumed by mobo?)

Just thinkin'.
Ron
(Let us know, please.)

Oh I'll definately let you know what the remedy or cause of it turns out to
be .... if I get one{:0).... then if someone has the same probs it'll be
half the battle for them!
Thanks for your suggestions thus far anyway ....

 

[Tomg]

If the current suggestions don't work, try removing the MB from the case and
checking to see if there are any extra stand-offs under the MB that don't
line up with the mounting holes in the MB. Sometimes, if you have extra
metal stand-offs, they'll short out on something and cause the MB to not
function properly.

Good luck,
Tom

 

[gw]

Green light on the MB lit?
Have you switched the power switch connectorf on the mobo?

gw

 

[Nero]

"apply new thermal grease "
It's not grease,it is thermal compound or if you must, paste.
Grease is used on auto parts and other moving parts and not in PC's.

 

[Nero]

Standoffs do not come ready fitted in a case unless the case was part of a
ready built system and even then when changing boards "anyone" should be
able to see if there are standoffs in the wrong places.

 

[Nero]

"Have you switched the power switch connectorf on the mobo"
???????????????
How can you switch the power switch connector ?? on the mobo ??
what do you mean?

 

[gw]

Sorry, what I meant is the power switch connectors from the case to the
mobo.

Green light on mobo?

 

[PhilM]

Hi again all

When I spoke to him about how he fitted the HSF ( which is what I meant to
say earlier sorry,not the CPU!) .... I asked him if he'd laid it dead flat
onto the CPU.
Turned out he hadn't - it was his first build and had put it on at an angle
and then laid it flat creating the same effect as a rolling pin has ie)
squeezing the thermal paste outwards (if you understand what I'm trying to
say)and ending up possibly with no/too little paste at the initial point of
contact.
Anyway he said he'd redo it and place it flat onto the CPU next time, which
he did, and Bingo everything powered up fine and he's now kicking some butt
with his beasty new graphics card and he's over the moon!
Looks like the Asus board must have this thermal cut out protection after
all!

Many thanks for all you efforts in resolving the problem.

Cheers and Merry Christmas.
Phil