I have pentium 4, intel 775 dual 915gl motherboard from asrock and ddr ram of 512 mb. my problem is no display on my monitor but the monitor works well on another system. The monior LED blinking. The processor, fan and harddisk works well. but there is no beed sound I tried to reset biios by removing battery but no response. i think my bios has the problem. how to solve this problem please help me quickly as possible thanking you

Do you see any POST screens on the monitor before Windows starts? Are you using onboard video or an add in card?

Nothing you wrote identifies the BIOS as the problem. Do you hear any beeps when you try to boot up?

"The processor, fans and hard disk work. . ." How do you know? If the drive motor and fans are spinning it only means they're getting 5 and 12 volts. (They probably are OK but fans and drive motors spinning doesn't verify that.) Likely your problem is with the motherboard and/or PSU. What happened to it between the last time it worked OK and the first time it didn't.

I once saw this exact problem on an amd based system (I think it was an athlon 64 3300+ or something similar). The only thing that got it to boot was a new processor; the original processor was supported by the board according to the documentation, I didn't try it in any other pc because it wasn't mine, went back with the people I fixed the pc (ebay special) for. Many things can cause these symptoms as mentioned above, I have seen it caused by corrupted cmos, but it is unlikely. None the less it shouldn't hurt to try clearing the cmos again with minimal hardware connected (cpu ram and graphics) by removing the battery and if available using the jumper. Try to boot with the minimal hardware connected. It depends on how in depth you want to trouble shoot it, I would slowly strip it down until all that was left was a know good and tested PSU, speaker and power switch connected to the motherboard, testing periodically along the way, but it may not be worth it....... If this is a result of a bad bios flash, you could try the recovery techniques. Or uniflash in a "hot swap" on another mother board (and if it really a bad bios chip a compatible one) as a last resort.