Hello my friends
I have seagate Barracuda ATA III, Model ST320414A, 20GB, FW 3.05, when I connect it to computer, the computer/PC turn off. What is wrong with hardisk ? How to solve this problem ? I was check the PCB and It is oke.
Please help me.

Try to do not connect it "on the fly"

google -> TRANSIL, TRISIL, TVS

Hi MonRepos,
actually this was a little joke
To sigitharjono,
First of all you must concretize if your PC do not power ON, or turn OFF when working.
If you use 40 pin IDE cable (or so called ATA33) you must check the position of the pin 1. It is marked with red. There are some old cables that do not have guide and also pin 20 is not blocked. ST320414A Configuration and Specifications
Pin 1 must be orientated to the power supply of the drive. i.e red to red (5v). Also the connection to the MB must be checked too. To exclude cable problem you must try other cable and also try to use secondary instead of primary chanel.
I do not know what you mean by pcb-Ok, but at least you must not have short in 12/5v and GRND.
Check PSU if it can hold your system, Cpu, Cd/Dvd burners, Hdd, Video, cooling system....
Also do not connect the drive on the fly(except this function is not supported by the MB and/or other specialized h/w), this could turn off the PC

Hello Friends

If Hardisk connect to others computer, the problem is same (the computer turn off). If PCB from the defect hardisk connect to defect free hardisk with same model, FW. It is normal.

Thanks