Computer turns on but won't boot up.

Gateway SX2800-03
Windows Vista Home Premium 64-bit with SP1
Video - Intel GMA X4500 Integrated
Optical Drive - DVD-Super Multi Drive with Label Flash
Processor - Intel Core 2 Quad processor Q8200
Memory - 4 GB DDR3
Hard Drive - 640 GB
Memory Card Reader - Multi-in-1

This problem started yesterday morning. The computer had been freezing up so I held the on button down to turn it off. When I woke up yesterday it wouldnt boot up. It would turn on, I can hear the fan but it wont' do anything else. I have tried the f8 and the Alt+FN+F10 and nothing happens. I don't know what to do as I am not knowledgeable in this area. I really don't want to buy another computer as this one is only 2 1/2 years old.

I have read other posts but can't find anything that will help me.

Any help is greatly appreciated. Thank you.

 

how wiling are to open the pc case and search the things from inside??
take of the power supply out of mobo also from the plug
keep that for a while. reset the bios
then plug back the power to the manboard plug it to the wall
and try to boot

if it fails
remove all hard drives optical disk
any cards in the mobo and try to boot with that

if it fails
do you have any graphic card to test??
maybe the onboard is dead thus you can not see anything when you open it

if it fails
check the memory
if it is 2 modules start with each one to see if it will boot

good luck

 

If you are unsure of where the CMOS Jumper is its normeally close to the motherboard battery, (which is a small silver circular battery) at the lower end of the Mobo, close by you will see a 'Jumper' that has three pins, it will be set to pins 1 and 2 Pick the Jumper up (which has a plastic coloured top) and move it to pins 2 and 3 leave for 20 secs and reverse putting the jumper back to 1 and 2. Power on and start computer then post back with result.