Pc keeps crashing - HELP

[clarkey01]

My pc keeps making a whistling noise on start up and sometimes just shuts off, I flick the switch off at the back for a few seconds, thne turn it back on and start up and the same thing happens, most of the time, the 2nd start up will be sucessful, but it still makes this whistling sound.

I have sent the manchine in and it didnt happen at thier shop and they could find no wrong with it, However when i get back to my place it does, and when the side pannel is off theres no problem at all. Fans are clean and I cant THINK OF ANYTHING it could be.

Help me I beg ;-(

 

[montag451]

heat?
The whistling sound might be a fan on its way out.

put your ear [making sure your long dusky hair is tied back] to the system when it is running without a case, and see which area the noise comes from.
It might be worth disabling the CASE fans, not the cpu fan one by one to see if one of them is making the noise