[Solved] Mobo Fail to boot

Hello,
Recently i experienxce fail booting, mobo give a long beep sound. I try to reboot but nothing happen, try to off power & on again to start pc & problem persits Ater on off power few time, it;s getting worst. There is no power that supply to mobo. I think may bcoz i on & off the power to restart pc. This is the only way to restart my pc.
What is the meaning for the long beep when booting. I did try remove all the hardware, with an without RAM but i still got the long beep. Finally on & off the main power try to reboot and tis action cause the power supply die too. The power supply is only 2 months old. Any suggestion apprexciate.
My PC build with;
Intel Pentium 4 2.4G
P4MAM-V MSI mobo
Hitachi 160 HDD
Kingston 1gb DDR
Window XP SP3

Do u check the mobo's manual to know the means of that beeps?

Check the installation of the CPU cooler, could be not fully adjust and reset the BIOS of the mobo.

Yeah the Clear CMOS is the same that rest the BIOS.

After reset the BIOS remove the battery for 5 seconds, the only problem that can cause the battery is an outdate time but not boot problems.

Download and use Everest to now the current BIOS version that u have.

It's not necessary remove all the drives since the BIOS reset don't affect the OS or other components of the rig. U don't need change anything just leave it and boot to OS.

Dear Saint,
After replace batt & reset CMOS, It stil give a long beep. After few try, finally can boot. What I do is
1) booting without all the ribbon cable attach to mobo -- fail
2) booting wthout RAM-- fail
3) re-insert RAM & reboot -- fail
After few try it finally success. I'm not sure which above step is causing the success boot.
Actually before the long beep fail booting happen (that first I post on the forum) my pc sit idle for about 2 weeks. I'm doubt if again idle for few days it happen again.
base on your experience, can u see what wrong. Hope to hear from you soon.

After replace the PS, & start pc, to my suprise that still the same (only the fan that attach to the CPU & PS rotate about 3 second ony & nothing happen after that nor with any beep sound) despite few attempt to start pc. At this point I start thinking that there is nothing wrong with the PS. This is confirm after I remove the RAM & start pc, all fans operate normal back but give along beep sound WHEN BOOTING. So as describe earlier to start pc with remove & re-insert RAM that finally ok. After re-insert RAM i did not do anything but try to reboot, is it something to do with RAM slot or the RAM piece or else. I did try slot the RAM to another unsed slot but still can't boot. Can it explain that it simply cannot detect the RAM & emit one long beep?

It could be. I'll try another compatible RAM & see when the issue arise again. I did ask the tech savy guy, said probably the RAM or the ram slot may defect & will give you a long beep. But since the sucesful booting, the pc are working fine. I will post again if any issue arise. Thanks.