During POST it automatic goes to no signal on screen

[Rap15_06]

Hi. im new of this site hopefuly someone help me.
my problem is yesterday when i using my computer it suddenly
shutdown, then i turn on it again but on the POST the only appear
is usb controller then pres F11. the cd rom and hdd didnt appear
and also other drivers in my computer didint appear during the POST.
so i press F11 after i hit F11 the screen gone and appear "no signal"
in the same time the computer fun also stop working. i unplug the
cable and turn on again and no appear anymore on the screen. i try to
remove RAM and put again, i try to clean the fun, i try to disconnect all cables
and connect again but no luck. after 10mins i turn on it again and same has happend
during POST only usb conrollers and press F11 appear after hit F11 it goes on "no signal"
. how i know what the cause of this problem?? plss help.

 

[DelroyMonjo]

What kind of computer?

 

[Rap15_06]

i forgot what the name of computer. actually it's my uncle computer.
im suspect that the motherboard was getting bad but maybe not because when i turn it on the POST was still appear.

 

[Rap15_06]

how do i know if either motherboard is bad or power supply??

 

[jaquith]

The 'typical' signs of a bad PSU are sudden shutdowns as Windows is loading, running intensive Apps or Games (raising load), or erratic behavior.

Problem, that often can mimic a bad MOBO -- the tell tail is the load. Unfortunately, the only way of knowing is to try a new and adequately sized PSU. If this is an older PC and you added 'stuff' e.g. new GPU then quite often it's the PSU, as a PSU get older it can loose 20%~30% of its' capacity.

Worst, a failing PSU can cause damage to the other components e.g. MOBO, RAM, CPU, GPU, etc...

 

[Rap15_06]

@jaquith.

wow. thanks for the useful info actually my uncle's computer is older and old model.
he said its almost 3 or 4 years old his computer. its my first time to encounter that computers problem. actually im familliar of computer and i do troubleshooting because my course is comptech. but this case i cant figure out whats going on i had one day already trying to fix my uncle's computer.

when i turn it ON during the POST the things that appears is usb controller and press F11 the rest was not appear meaning the rest was not detect during the POST and its only stop there after pressing F11 its turn off and appear "NO SIGNAL"
and the button light of monitor was orange.
my suspect is the motherboard, RAM and PSU.
any idea whats going on??
please help!

 

[Rap15_06]

the windows that running in that computer is Windows XP.

 

[JKatwyopc]

Try working through this: http://www.tomshardware.com/forum/261145-31-perform-steps-posting-post-boot-video-problems

Be very thorough and don't skip anything.

 

[Rap15_06]

Thanks for advice!
my uncle's also said that sometimes when they playing games at the middle of games
the computer suddenly restart.
and the fan also stop working. when turn on the fan works again.
any idea?? thanks.

 

[Rap15_06]

and also when i turn it ON the computer still doing a POST and only appear is
USB controller press F11 and CPU Speed something like that.
after pressing F11 it will turn of the screen and got "no signal" and the botton color of monitor turn to orange and the fan stop working after pressing F11.
any idea pls??