Suddenly PC wont POST - Tried the usual suspects now what?

[aqil]

My PC has been running fine for the past 4 months until yesterday. It had been connected to an LCD TV for a few days so I shut it down, switched DVI cables back to my LCD monitor, turned it on and no POST.

The motherboard LED lights up, case and CPU fans spin but no activity from the monitor and no POST. Connected a motherboard speaker and no beeps. Just to test if the motherboard beeped I took out all the RAM and it beeped like it should. Does this mean the motherboard is OK?

I have tried unplugging the sound and graphics card, hard drives & CD (CPU & RAM only) and booted up and still no POST

I have taken out the battery and cleared the CMOS and just now reseated the CPU and still nothing

Any ideas what could be wrong? I bought all the parts back in November from Scan so I guess if anythings faulty I am covered by warranty but how do isolate the problem.

Heres a component list if there are any known issues

Intel Q6600 GO
Scythe Mine Cooler
Asus P5E
2x Crucial Ballistix 1GB PC2-8500
WD Raptor 75GB

Any help appreciated.

[AndrewJ]

Does it work if you plug it back into the LCD TV? it could need reconfiguring to a normal monitor before you shutdown and change back.

[Splash]

No beeps unless you take out the RAM? I'm looking at the RAM then to be honest. Can you test some known good memory?

[Lucio]

Try clearing the capacitors. Unplug everything and hold down the power button for 30 seconds or so.

[peterb]

Try clearing the capacitors. Unplug everything and hold down the power button for 30 seconds or so.

Why??? What is the rationale behind that suggestion. given that the capacitors will discharge thyemselves pretty quickly.

[Splash]

Why??? What is the rationale behind that suggestion. given that the capacitors will discharge thyemselves pretty quickly.

I was rather thinking the same of AndrewJ's suggestion - how is switching from an LCD TV to a TFT monitor going to stop a machine from POSTing?

[peterb]

I was rather thinking the same of AndrewJ's suggestion - how is switching from an LCD TV to a TFT monitor going to stop a machine from POSTing?

Yes, I thought that too - definately looking like a memory problem - differential diagnosis would be PSU

[Splash]

PSU is another possibility, maybe even a motherboard short.

[Lucio]

Why??? What is the rationale behind that suggestion. given that the capacitors will discharge thyemselves pretty quickly.

Silly as it sounds, I've had a fair few systems get "stuck" with a similar screen issue and after spending hours and hours looking for a solution, I tried this and it cleared it up.


I don't understand the reason why this helps things, but it does seem to clear up issues caused by a small ripple in the power supply (for example, slightly loose power cable gets knocked, cat turned off the multi point adaptor etc). Even weirder with my g.f's PC this happened the day AFTER the multi point was turned off, despite being a couple of times having it turned off and back on.

My rationale is that he's knocked the power lead slightly whilst changing the cabling.


All in all, it's just a suggestion from someone who had similar symptoms on another PC and he's tried a lot of other comprehensive testing, so I thought I'd offer up a simple, but often overlooked, idea.

[peterb]

Ok - interresting thought - although I can't think of any technical explanation why it should work!

[aqil]

Thanks everyone for your replies. As I had no other parts to test with I took it to a local PC store who had some spare parts.

First thing we tried was new RAM and guess what it POSTed.

What are the chances of that, two 1GB Crucial Ballistix 1066 sticks dead. My question now is do I replace it with the same or does anyone have any better recommendations for my setup.


Thanks all.

[Splash]

The Ballistix is a decent range, and as you mentioned earlier that it's under warranty I'd just get it RMAd and replaced.

What PSU are you using out of interest? And were you overclocking (not that you should be pushing that RAM with a Q6600 overclock unless it was something crazy...)?

[aqil]

I have the Corsair HX520W PSU. Have not overclocked it, still amazed by the stock speeds.

Curious about your comment on overclocking, you mean if I was to overclock I would not need to push the RAM any further?

Thanks

[Splash]

There's a lot of overhead in that RAM - you could overclock your CPU (theoretically) quite some way without having to overclock your RAM. If running at stock you may have paid a little more than you needed to for something that you're not going to get full use of.

[aqil]

Thanks Splash for your insight. I do plan to overclock and have been researching the subject.

I had some experience overclocking my old system (P4 Northwood & an Asus P4P800) however it was somewhat easier as it just had the option to overclock in increments of 10, 20 and 30% which took care of all the settings.

Are there any recent overclocking guides you are aware of which are based on my specs e.g Q6600 & 1066 RAM which I can read up on.


Thanks

[Splash]

Clunk put together a VERY comprehensive guide to overclocking the C2D/C2Q - I believe it's stickied somewhere.