Recently, my computer freezes whenever I'm only about 5-10 mins into gaming (mini ninjas, sims 3). And when I reboot my com immediately, it hangs during start-up, or would go into sleep mode. This problem only started last week, and I was able to play the games without any problems before that.

my computer specs:
- OS Windows XP SP2
- Motherboard ASUS M4A785TD-V EVO
- AMD Anthlon II X4 630
- 2G DDR3 RAM
- ATI Radeon HD4850
- 550W Power Supply

I need some help to resolve this. Thanks.

Hi Tan and welcome.

You describe classic heat problems. I suggest you start by making sure the interior is free of heat trapping dust, and all the fans are working fine. See my sticky, http://www.d-a-l.com/help/general-ha...aning-esd.html.

Thanks for the reply, the information was really useful.
However I don't think heat might entirely be the issue, as I'm still encountering problem after I've cleaned up.

To give you a clearer picture, I'll re-describe the scenario.

I upgraded my com with these new parts early in April:
- Motherboard ASUS M4A785TD-V EVO
- AMD Anthlon II X4 630
- 2G DDR3 RAM

I also just cleaned my com before having it upgraded.
The com was working fine until a couple of weeks later where I started encountering some problems:
- computer freezes while playing games
- computer hangs during start-up when restarted immediately
- computer doesn't even boot when I start it (fan spins and all, but com doesn't 'beep' and start to boot)

So I took your advice and cleaned my com again.
I suspect it could be some virus or what not, so just to be sure, I formatted my hard disk too.
Right now the com is still having problems. Sometimes it works fine, and other times I still encounter the com not booting when I start. I haven't install and tried playing games yet.
But looking at it, it's probably a hardware issue.
Maybe the new hardware, or a power issue?

Would need some help here, thanks.

computer doesn't even boot when I start it (fan spins and all, but com doesn't 'beep' and start to boot)

Maybe the new hardware, or a power issue?

Not booting could indicate a PSU problem. Do make sure all connections are tight and secure.

Did you use a proper layer of http://www.d-a-l.com/help/general-ha...-material.html? You might run with one stick of RAM for a bit and see what happens, then swap it out one a time.

I only have 1 stick of RAM unfortunately, so I can't swap it about.

I figured that the problem of my computer not booting when started could be because the power cable isn't tight.

However I'm still facing freezing problems, not just when playing games but even when doing less intensive stuff (web surfing, listening to songs, etc). The freezes are really inconsistent (5 mins into usage, hrs, or not at all), making it difficult to determine what might be the cause.

The cause should not be the graphics card, because the problem persists even when using the on-board graphics of my mb.
Heat should also not be the issue, because the problem can happen even when my computer is almost idling (temp readings cpu: 42°C, mb: 40°C). I've tried running with and w/o the computer case.

Could it be a case of the power supply not supplying consistent voltage or something? It's about 2 years old. Any ways to determine which individual hardware could be the cause of the inconsistent probs?

Could it be a case of the power supply not supplying consistent voltage or something?

Yes. A failing or stressed PSU can cause all sorts of odd problems.

Below is my canned text for testing PSUs, and below that is my canned text for testing RAM.

To properly and conclusively test a power supply unit (PSU), it must be tested under various realistic "loads" then analyzed for excessive ripple and other anomalies. This is done by a qualified technician using an oscilloscope or power analyzer - sophisticated (and expensive) electronic test equipment requiring special training to operate, and a basic knowledge of electronics theory to understand the results. Therefore, conclusively testing a power supply is done in properly equipped electronic repair facilities.

Fortunately, there are other options that are almost as good. I keep a FrozenCPU Ultimate PSU Tester in my tool bag when I am "in the field" and don't have a good spare power supply to swap in. While not a certain test, they are better than nothing. The advantage of this model is that it has an LCD readout of the voltage. With an actual voltage readout, you have a better chance of detecting a "failing" PSU, or one barely within specified ATX Form Factor Standard tolerances. Lesser models use LEDs to indicate the voltage is just within some "range". These are less informative, considerably cheaper, but still useful for detecting PSUs that have already "failed". Newegg has several testers to choose from. All these testers contain a "dummy load" to fool the PSU into thinking it is connected to a motherboard, and therefore allows the PSU to power on, if able, without being attached to a motherboard - great for testing fans, but again, it is not a true load or suitable for conclusive testing.

Swapping in a known good supply is a tried and trued method of troubleshooting, used for years even by pros. If you have access to a suitably sized, spare power supply, carefully remove the suspect supply and replace it with a known good one and see if the problem goes away.

I do not recommend using a multimeter to test power supplies. To do it properly, that is, under a realistic load, the voltages on all the pins must be measured while the PSU is attached to the motherboard and the computer powered on. This requires poking (with some considerable force) two hard and sharp, highly conductive meter probes into the main power connector, deep in the heart of the computer. One tiny slip can destroy the motherboard, and everything plugged into it. It is not worth the risk considering most multimeters, like plug-in testers, do not measure, or reveal any unwanted and potentially disruptive AC components to the DC voltages.

Note the required voltage tolerance ranges:

And remember, anything that plugs into the wall can kill. Do not open the power supply's case unless you are a qualified electronics technician. There are NO user serviceable parts inside a power supply.

***

You can test RAM using one of the following programs. Both require you to create and boot to a bootable floppy disk or CD to run the diagnostics. Allow the diagnostics to run for several passes or even overnight. You should have no reported errors.

Windows Memory Diagnostic - see the easy to follow instructions under Quick Start Information.
or
MemTest86+ (for more advanced users) - an excellent how-to guide is available here.

Alternatively, you could install a single RAM module and try running with that to see if it fails. Repeat process with remaining modules, hopefully identifying the bad stick through a process of elimination.