Getting Crashes!!

Hi guys, when i play 3D games my pc crashes to a blank blue screen or a windows error message! I am pretty sure its an overheating problem of some sort because when i point a fan onto the motherboard with the case off the problem goes away for good!! When i put the case back on i get the problems again.

I know its not a defective RAM and i know the CPU isnt heating up because i reapplied some new thermal grease and i have a program that measure the CPU temp and it gets to around 35*Celcius before it crashes. I have also added 2 intake and 2 exhaust fans but this has made no difference when i put the case back on. All fans are working, especially the one on the video card. I have noticed however that when the pc crashes with the case on the psu is quite hot because when it crashes i immediately take the case off and i felt the psu to be quite hot. Not hot enough so that i cant keep my hand on but still hot compared to how cool it stays with the case off and the fan being pointed at the motherboard.

I am pretty sure its overheating but what else can i do to solve the problem other than adding more fans???....its only a household computer...nothing for extreme gaming but i still like to play games every now and then.

My specs are:
- P4 2.4GHz with 1gb ram
- 9600XT video card
- 500w psu
- Windows XP

If you think it is the power supply then replace it.

With your spec a 500W PSU is far more than enough (probably not if you are using some really cheap, massively overated one).

http://www.scan.co.uk/search/search....380w&Submit=Go
http://www.scan.co.uk/search/search....350W&p=2&t=Yes
There are quite a large range of replacements available around 350~380W for cheap.

Actually i have noticed that there are no problems with the fan not on but the case open. So just with the case open without the fan blowing it works fine...pretty weird.

Just last night I fixed a friends computer with a similar problem. His graphics card fan was spinning away, but dust had built up in the cooler, blocking the radial heatsink fins. So no air was flowing over the heatsink. 30min careful work with a paperclip and it was fixed. Working stable now.

Or it may be the PSU. A good 500W should be fine, but a cheap one often causes problems.

Do you guys recommend any good power supplies that arent too expensive??

Before you buy a new psu check your graphics card as Fabula suggested as I've had the problem as well where the vents were blocked and my card overheated.

I have actually had instability with my hiperpower type r 480w (quite a good and well known psu) overheating as it draws in all the heat from the other components. Usually this is fine but there is only a 120mm fan on the bottom but that pushes up and since the whole body was mesh anyway some air was just going back into my case still hot, basically the air was being drawn into my psu but wasn't being pushed out of the back of my case and the solution was to mount an 80mm fan on the back of it! (lol still cant believe i did that)

So you may want to check if any air is actually leaving the back of the psu and then if not maybe go for a cheap psu that pulls air in and pushes it our the back too. Personally i can vouch for this budget psu as i have built two pcs with this psu and ati x800xl's which are a lot more demanding than the graphics card you mentioned.

Edit= i also meant to say the fact that it has a fan on the bottom and at the back so quite good airflow.