New build problems - please help

[dmiskin]

I have recently built a new computer and i am having teething issues, i am completely confused about the cause of these problems. i would be grateful if anyone could help.

the first of my problems is that sometimes when i turn my pc on the fans on the outside light up the cpu fan starts but nothing happens on the screen. "loading asus express gate" doesn't even appear. sometimes holding down the power button turns the computer off. sometimes it dosn't work. when this happens normally i need to wait 10 minutes then when i turn it back on it works fine.

Another problem i have had is that the computer can randomly freeze when not in a full screen game. it has happened running itunes and on safari or even when welcome appears on startup. i know my pc is not overheating as under lode in mafia 2 the core temp is always below 50 Celsius using stock heat sink and paste. i have Installed all updates including graphics drivers. i cant remember this happening before updated the bios in asus update.

all components in my pc are if this helps

1 x Casecom 6788 Black Mid Tower Case with Full Black Interior/Exterior 120mm Blue LED Front Fan - No PSU
1 x Samsung HD103SJ Spinpoint F3 1TB Hard Drive SATAII 7200rpm 32MB Cache
1 x Corsair 4GB DDR3 1333MHz Memory Module CL9(9-9-9-24) 1.5V Unbuffered Non-ECC
1 x OCZ Stealth Xstream II 600W PSU - 3x SATA 2x PCI-E 204353 Invoiced Track
1 x Microsoft Windows 7 Home Premium - Licence and media - 1 PC - OEM - DVD - 64-bit - English
1 x AMD Phenom II X4 965 Black Edition 3.4GHz Socket AM3 8MB L3 Cache 125W Retail Box Processor
1 x Asus M4A87TD/USB3 870 Socket AM3 8 Channel Audio ATX Motherboard
1 x Nexos Molex Hub - Turn 1 Molex into 4 - Blue LED Light Effect
4 x 120mm Blue LED Fan - 4pin Molex Connection
1 x Arctic Cooling Freezer 7 Pro rev 2 Socket 775, 1156, 1366, AM2, AM3 Heatpipe CPU Cooler /not installed
1 x PALIT GTS 450 SONIC OC 1024MB GDDR5 Dual DVI VGA HDMI Out PCI-E Graphics Card
1 x Startech 4 Pin P4 CPU Power - Extension Uk

Any replies would be greatly appreciated, thanks

 

[jsc]

My first though tis either the PSU or the motherboard.

Work through our standard checklist and troubleshooting thread:
http://www.tomshardware.com/forum/261145-31-read-posting-boot-problems
I mean work through, not just read over it. We spent a lot of time on this. It should find most of the problems.

If not, continue.

I have tested the following beep patterns on Gigabyte, eVGA, and ECS motherboards. Other BIOS' may be different.

Breadboard - that will help isolate any kind of case problem you might have.
http://www.tomshardware.com/forum/262730-31-breadboarding

Breadboard with just motherboard, CPU & HSF, case speaker, and PSU.

Make sure you plug the CPU power cable in. The system will not boot without it.

I always breadboard a new build. It takes only a few minutes, and you know you are putting good parts in the case.

You can turn on the PC by momentarily shorting the two pins that the case power switch goes to. You should hear a series of long, single beeps indicating memory problems. Silence indicates a problem with (in most likely order) the PSU, motherboard, or CPU. Remember, at this time, you do not have a graphics card installed so the load on your PSU will be reduced.

If no beeps:
Running fans and drives and motherboard LED's do not necessarily indicate a good PSU. In the absence of a single short beep, they also do not indicate that the system is booting.

At this point, you can sort of check the PSU. Try to borrow a known good PSU of around 550 - 600 watts. That will power just about any system with a single GPU. If you cannot do that, use a DMM to measure the voltages. Measure between the colored wires and either chassis ground or the black wires. Yellow wires should be 12 volts. Red wires: +5 volts, orange wires: +3.3 volts, blue wire : -12 volts, violet wire: 5 volts always on. Tolerances are +/- 5% except for the -12 volts which is +/- 10%.

The gray wire is really important. It should go from 0 to +5 volts when you turn the PSU on with the case switch. CPU needs this signal to boot.

You can turn on the PSU by completely disconnecting the PSU and using a paperclip or jumper wire to short the green wire to one of the neighboring black wires.
http://www.youtube.com/watch?v=5FWXgQSokF4&feature=youtube_gdata

A way that might be easier is to use the main power plug. Working from the back of the plug where the wires come out, use a bare paperclip to short between the green wire and one of the neighboring black wires. That will do the same thing with an installed PSU.

This checks the PSU under no load conditions, so it is not completely reliable. But if it can not pass this, it is dead. Then repeat the checks with the PSU plugged into the computer to put a load on the PSU.

If the system beeps:
If it looks like the PSU is good, install a memory stick. Boot. Beep pattern should change to one long and several short beeps indicating a missing graphics card.

Silence or long single beeps indicate a problem with the memory.

Insert the video card and connect any necessary PCIe power connectors. Boot. At this point, the system should POST successfully (a single short beep). Notice that you do not need keyboard, mouse, monitor, or drives to successfully POST.
At this point, if the system doesn't work, it's either the video card or an inadequate PSU. Or rarely - the motherboard's PCIe interface.

Now start connecting the rest of the devices starting with the monitor, then keyboard and mouse, then the rest of the devices, testing after each step. It's possible that you can pass the POST with a defective video card. The POST routines can only check the video interface. It cannot check the internal parts of the video card.

 

[dmiskin]

Thanks, ill work through that now, what confused me was that the system works perfectly most of the time. However once every few days it refuses to boot. I will also buy a system speaker to help identify the problem.