im having trouble with my pc and its now getting beyond a joke.. my pc has now got a habit of just turning the monitor off and i also believe its shutting the pc down,(also tried 3 other monitors thinking it was just mine that was playing up) but i can still here the fans etc.. i can be sat here for ages turn the pc on & nothing... eventualy when its warmed up it will boot up (after about 20 tries) then nine times out of ten i will click on internet explorer or msn msg and click gone again........

i am completely stuck with what to do, i would apprieciate any help given but please write it in lamens terms cause i dont have a clue about this stuff, just want to surf the web....

also would like to say had this dell pc for about 4 years not changed any hardwear etc, havent really downloaded anything that i think would do this

please please help before this sends me mental


when this happens you need to look and see if all your lights and fans turn off also. if you had this computer for 4 years have you ever cleaned the inside. Computers will collect dust on the inside and the dust will eventually kill the computer. Clean the inside of the computer first before you do any thing else. if the computer still shuts off after you clean it then we will move on to troubleshoot the problem.

thank you for the reply.. i will make that tomorrows mission to clean it, i guess im just clearing dust i don't need to take things apart as such?? as for the lights, the pc power light stays on, & i can hear the fans etc but the monitor just goes into standby

many thanks

thats right just cleaning you don't have to take anything apart yet.

if it is just your monitor that turns off, try that monitor in a different computer and post back if the monitor works. also post what type of computer you have. I know its a DELL but what model is it.

i've tried 3 monitors and my lcd tv.. still the same problem

my pc is a dell optiplex gx270 pentium 4

again many thanks

ok there should be 4 diagnostic lights on the computer, when the monitor turns off look at these lights and see if they are on and see what color they are and post that here

on the back of my pc there are 4 green lights labled a,b,c,d... when the monitor dies all four of those go out? hope thats what i was looking for couldnt see 4 other lights


yes that is exactly what you were looking for. under normal operation all 4 of those lights should be green. the fact that all the lights are off indicates the the entire computer is shutting down. after you clean the computer post back here, and we can walk through step by step to see if we can find the source of the problem.

k, thank you very much for your help... will clean it tomorrow

well i've cleaned it... i.e blown all the dust out. but sadly no change


1. Have you checked your Power Options? It may be hibernating.

start/control panel/power options

2. Check your cpu temperature and cpu fan speed in the BIOS. It may be over heating.

If it's too hot... Replace the thermal grease between the cpu and heatsink. After 4 years it's likely that it needs replacing. The fan may also be beginning to fail as mine did the other day, so replace the fan.

3. It could be that the power supply is beginning to fail or may not have enough power if you've adding more hardware recently.

well i've cleaned it... i.e blown all the dust out. but sadly no change


ok sorry it took so long for me to reply,
move your computer somewhere so that you have room to work on it.

with the computer open I want you to turn it on and whatch the fans, do all the fans turn on.
check the fan in the power supply and any other fans in the computer. post back

sorry for the late responce, been away... i will start this troubleshooting this weekend

both fans turn on and when the comp dies both fans are still spinning


ok here's where it starts to get a little more complicated. both fans still turn when the computer dies tells you that the power supply "should" be ok, it would have to be tested to find out for sure.

the possible causes for your computer to turn off like that are

1. the CPU could be bad or overheating

2. the motherboard itself has gone bad

if Dell still does this, there should be a cover from the case fan to the CPU heat sink, if not then there needs to be a fan directly on the heat sink on the CPU

if the cover is there then check to see if the case fan is spinning fast enough or possibly replace it.

also make sure that the heat sink over the CPU is clean. you will also want to carefully take the heat sink out and apply some thermal paste between the CPU and the heat sink. IF you take the heartsick out and the CPU is stuck to it and you have to pry it free from the heat sink then you should just go ahead and replace the CPU. You can find refurbished CPU's on the internet for not allot of money. you also need to pay attention to the orientation of the CPU there should be an arrow in one of the corners thats the way the CPU needs to be placed into the socket and make sure you don't bend the pins.

but before you go through all that take a real good look at the motherboard. look at all the capacitors to see if any of them are swollen or leaking or look corroded if you see any of that then replace the motherboard.

if you don't feel confident enough to do any of those task then you should consider taking it to the shop to get worked on.

It is a motherboard problem.Just Google GX270 capacitors and you will get all the info you need.These and the GX 280 shipped with bad capacitors.They bulge,and rupture.The last chance to have Dell replace them free died on Jan 31st,2008.I know because I just got one in an auction for $5.00.I am going to try and replace the caps myself.A company called has the recap kit pretty cheap.From what I have found you only need to replace three of them.The three 1500uF 6.3v 10mm.They are in a row under the fan.Hope this helps.