I have a p4 PC with a gigabyte mobo ga-8st800. It try 5 times to start but then keeps beeping alarm. I checked its vga ,rams, all in other pc & they are working fine. I tried removing battery and all known stuff. But its not turning on. I dont think its busted coz I can hear cd-rom seek & hard disk check. Please help

That beeper is more than just a random alarm. Note down the pattern of the beeps (eg: long long short, or long short short or just one continuous beep). Then compare the pattern to the chart that should be in your mobo manual (should also be available on the product page at gigabyte's website, just google it). That will tell you where the problem is.

That beeper is more than just a random alarm. Note down the pattern of the beeps (eg: long long short, or long short short or just one continuous beep). Then compare the pattern to the chart that should be in your mobo manual (should also be available on the product page at gigabyte's website, just google it). That will tell you where the problem is.

thanks for ur reply . its a short continuous beep. Also I dont have a manual for that.

thanks for ur reply . its a short continuous beep. Also I dont have a manual for that.

Manual link http://download.gigabyte.asia/FileList/Manual/motherboard_manual_8st800_e.pdf

  Hi this is a power problem.... 
So first try a different Power Unit or so call PSU and check if you still get the error.....
then its time to Check your power regulators in your Mainboard with a multimeter if you don't know how google it ....
once you find the fault add some flux & remove the power Regulator/Regulators with a heatgun or rework station.....
get the part from a electronics shop or if you cant find it get it from a old 350w Power unit.(Most Power Regulators are the same like LM7808,7812,etc)
Add flux and trim down the pins and solder as necessary (use no clean flux so you wont have to clean the flux afterwords)
then your done mate..............................................................Bravo you just did a Motherboard Chiplevel Repair

Just forgot to tell you a little thing,

 if you check power regulators in the motherboard keep a good eye on blown or leaked Capacitors. If your board does have Solid Caps you cant tell the difference of a blown cap for outside without checking.The power regulator or rectifier closest to a blown cap is faulty 98% of the time.
wish you all the best mate

If the motherboard uses AWARD BIOS, short beeps would mean overheating CPU. Check if the CPU fan is spinning and that the fan is plugged into the mobo properly. You didn't change the fan or reseat it recently right? Did you do something that might have knocked the heatsink loose?

If they've changed the beep codes or something, it could also be a memory error. You checked the RAM in another PC and it worked? If you have quick access to another PC, why dont you try using RAM from that PC in your one? It's worth a try to know that it isn;t the RAM slot that's causing the problem.

@Dave: if it was a PSU issue I doubt it would remain on and beeping. Also, attempting self repairs is a HORRIBLE idea unless you're extremely experienced with a soldering iron. 99.9% of amateur repairs probably end up in failure and even if it doesn't fail right away, I bet it will before long. Even if the repair works it'll be working at sub standard quality.

If your PSU has any issue, REPLACE IT. Or you'll get magic smoke soon. Same with blown caps. 1 blown cap means it's time to replace the mobo.

Actualy this repairing thing is very risky. I checked  each  256 ram on other PC & checked with its both 256 rams in this PC. Also I removed processor all the way & set it all again. Thing is PSU is a almost new 450W. I can check it with my core2 PC.
But the thing is that the pc starts with no video,then hard & cd-rom seek 5 times , blinking power light + continuos beep.... all the fans are working too ..