yes the fan of the power supply comes on and there is no been all the rams are working well because i put them on the other pc and RAMs are working well. the problem is that when i press power button the cpu starts but the light blows yellow not green and there is no display comes on monitor screen and no light in the optical mouse and keyboard. whern ever microprocessor and power supply fans are still running.
If it has an add- on video card try and remove it and use the on-board video if it has that. If not then get a Power Supply tester and test the power supply. I know these are somewhat random suggestions but,I'm with rch1231, is there any more info you can give us?
Where is the yellow light on the M/board or the monitor? On the board=No POST(1), On the monitor=No Video signal/output
if (1) Check to make sure the RAM/memory modules are the correct ones for the system (Unless you know this already)? Use insert one at a time to boot the system.
Check the PSU, as above or borrow a known good working PSU from someone.
Try 'the simple system' With the system powered off! and earthed/drained (press the power switch with the power cable unplugged), first remove everything form the the system except the CPU, the speaker. and PSU connections and the power button/switch. Does it make any noise, it should produce some form of noise which says the ram is missing. Switch off, insert the Ram leave out the video card if possible assuming it has not got on board video card/chip. It should now POST and if you have the Video Card option you should get a beep sequence which tells you the Video card is missing. Switch off insert the Video card and try again. Once you have that go from there add components back until you have a working system
You need to check Your Mother Board Supply . it happens only , when supply comes in low voltage or any more resisitence accours in the way of charging a capicitor on motherboard . When Capictor Get complete charge it will Show Display . 90% fault in your Mother Capictor Charging Due to Low voltage supply to capictor by resisitance