Newly built computer not working (sort of)

ChasersR4wimps

So, my brother decided that he wanted a new computer and it seemed most cost effective for him to build it. Considering I had done a fair number of the steps of a build by myself and am pretty good at following directions I said I would help him get it up and running. We spent an afternoon taking our time to assemble it. So far as I know, we followed directions precisely. However, the computer is not working properly.

Right now the computer will post about once in five tries. When it posts the BIOS everything seems to respond properly (The CPU seems to be running a bit hot at 56 degrees idle). Strangely when the computer decides to post it will turn on for about half a second, turn off, and then come back on and post. This is the only time when it displays this behavior. When it does not post it gives no error beeps and the fans continue to spin. The computer actually has yet to make any noise through the small speaker attached to the mobo.

We have tried booting with only the ram, video card and cpu, along with reseating the ram and trying individual sticks. That seems to make no difference in the frequency of the computer posting the BIOS. Right now I am not quite sure the best route for troubleshooting. I feel pretty confident that we didn't botch anything on the installation but that might be a possibility. I know that we should have most likely submitted the parts list to the computer build thread but my brother decided to go ahead and order what we have now. I didn't see anything that I thought would cause a problem but I will post the list in case there is some obvious incompatibility.

MOBO- ASRock P45R2000-WiFi LGA 775 Intel P45 ATX Intel Motherboard
CPU- Intel Core 2 Duo E8500 Wolfdale 3.16GHz LGA 775 65W Dual-Core Processor Model BX80570E8500
RAM- OCZ SLI-Ready Edition 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit
DVD- LITE-ON 20X DVD±R DVD Burner with LightScribe Black SATA Model LH-20A1L-06
PSU- OCZ GameXStream OCZ700GXSSLI 700W ATX12V Power Supply
HDD- 2-Western Digital Caviar SE16 WD6400AAKS 640GB 7200 RPM SATA 3.0Gb/s Hard Drive
GPU- VisionTek 900244 Radeon HD 4870 512MB 256-bit GDDR5 PCI Express 2.0 x16 HDCP Ready CrossFire Supported Video Card

Thanks in advance for the help.

Dunadan019

reattach the CPU heatsink and make sure you arent using too much thermal paste.

on some MOBOs when the temperature reaches above 60 degrees it will shut down. this can be caused by the CPU fan "warming up" i know in my computer the temps reach 50 on start up but then go back down.

if you are using the stock heatsink consider buying a better one.

your power supply could be underamped for the 4870 but that wont cause a restart like an overheating processor will.

if reseating the heatsink doesnt work it could just be a generally bad mobo and you can contact the manufacturer or the distributor for an RMA

ChasersR4wimps

Thanks for the advice. We are using the stock heatsink with the thermal paste that was already applied. I am pretty sure that the cpu heat, though worrisome, is not the problem getting the computer to post. Usually the heat starts in the low 30's in the bios and then climbs as the computer is left running. Once the computer has already been running there have been no restarts or strange behavior. The only time when a restart seems to happen is directly after turning the computer on. The computer will be on for half a second and then shut off for 2 or 3 seconds then come back on and post. This is the only time when the computer will post. Whenever the system turns on normally there is no post and no response.

Currently we are thinking that either the power source or the MOBO is to blame. Would you advise RMAing both at the same time or just try one and then the other?

Dunadan019

try the mobo first, no need to pay for shipping unless you have to (unless you can send them both back to the same place.

Dixon

I doubt the 4870 is not getting enough from the 12v rail, thats a pretty good PSU. I would suggest you rma the mobo also. Intermittent problems always suck, do you have another system perhaps the old one you can just plug your new PSU into or do you have a PSU checker?

ChasersR4wimps

I do have another system but it is not nearly as power hungry as this one, I guess I could hook up the psu to it and make sure that it works properly.