Failing to post

ojrules · 5 Jan 2011 at 11:58

My machine has recently generated the problem of periodically not posting... It fails to post even after various attempts of restarting etc, then just 10 or so minutes later everything is fine. Its a relitavely rare occurance, but i can't put my finger on what is causing it, checked temps, all seem fine. Hasn't crashed in win7 for forever, it had been overclocked but i set it back to defaults after the first failure to post, but the problem has persisted. Any ideas at all on what i could check?

I have a ASUS p5q pro
E2180(?) (2ghz dual core)
4gb ddr2
4850 512mb
1tb f3 drive

any help would be much appreciated.

Plec · 5 Jan 2011 at 13:42

What's the make, model and age of the PSU?

If you haven’t done so already I would start off with resetting the CMOS and then loading optimised defaults.

Also try reseating all your connections (unplug and reconnect) – including SATA and front panel pins (and kettle lead). And make sure that all your components are seated securely in their respective slots.

Also ,make sure that the motherboard is securely fitted and that there isn’t any movement between the board and the risers.

If none of the above has any effect then testing your PSU with a voltmeter would be another logical step. I'll dig out a link of how to do this if you need one...

EDIT: If none of the above works try one stick of memory and alternate if necessary in different slots - and run memtest.

ojrules · 8 Jan 2011 at 22:24

-- thanks very much for the response--

The power supply in question is an enermax liberty- elt620awt - maybe 2-3 years old.
I checked connections- although havn't gone round unplugging and replugging like you suggested, - lazyness not arrogance

-
I reset the cmos, tried with one stick, with no avail.
Then suddenly after many many tries at turning it on and inspecting the motherboard, it turned on.
When it doesnt post, it turns on fine, but just freezes on the motherboard page, with instructions as normal to press del to enter setup etc.
- If the mouse lights up i know it's going to work, otherwise it'l just sit on that screen.-
It hasnt turned off or crashed whatsoever once past posting.

I have some rather important exams in the next few weeks so could really do with being able to use it... What would the implications of leaving the computer in sleep mode be for extended periods of time (days at a time)?- once the computer is past post mode it doesnt crash, even after being in sleep mode-

Any other insights would be much appreciated, although unless something is obvious i appreciate i havnt tried properly testing the power supply etc yet..
muchos thanks

Infam0us · 8 Jan 2011 at 23:42

Had exact same symptoms as you for a few months, eventually got that bad it would'nt boot at all. Twas the Mobo that needed replacing, now it works great

ojrules · 9 Jan 2011 at 00:12

^^ thats encouraging :/ ... what was the model?- not the same as mine was it?

Plec · 10 Jan 2011 at 11:39

ojrules;18179268 posting. said:
I have some rather important exams in the next few weeks so could really do with being able to use it... What would the implications of leaving the computer in sleep mode be for extended periods of time (days at a time)?- once the computer is past post mode it doesnt crash, even after being in sleep mode-

With a perfectly running computer there are no concerning implications in leaving the machine on 24/7. I used to leave my computer on all the time and just do an occasional reboot when required.

So in theory you could leave you computer on – but you do have a problem and one that may eventually make itself known during normal operation and not just during post. But there still isn’t a problem in leaving your machine on as long as you back up your work (externally) and are prepared that the problem ‘might’ appear in a different guise during normal operation.

I’m afraid your problem could be one of a number of things motherboard certainly being a strong possibility.

When you do start to turn your computer off again you may want to try the following:

If you’ve tried all the things I suggested in my first post I would recommend trying a different power supply (if you can get your hands on one). This is a simple test if you have one to hand and eliminates a major component. If you haven’t got a spare PSU to hand you will need to test it with a voltmeter – click on the below links for instructions on how to do this:

'Use a multimeter to check your PSU' and one to 'How to check if your PSU is faulty'

If possible you would then try a different gfx card and memory to rule these out but I realise that not everyone has spare parts lying about. Perhaps a friend or family member has compatible components you could borrow?

It would also be advisable to run memtest for at least a few passes.

If the PSU passes as fit for purpose and you can’t get your hands on other spare parts to test then you will need to run a skeleton setup: CPU, 1 stick of memory (alternated slots and sticks if required) and gfx card – everything else unplugged from the motherboard. If the system boots consistently into the BIOS with this setup then reattach other devices one by one until the PC buckles.

However if the system still has the same issues with a skeleton setup then you have at least narrowed down the problem to possibly 3 devices (although the case would still be an outside possibility if you’re running the skeleton setup within the case). If you still can’t get hold of spare parts to test at this stage then you will have to take an educated guess.