Finding the right field effect transistor (FET)  

If you repair switch mode power supply, the most frustrated thing that you encountered is no original spare parts especially the fet field effect transistor. Some equipments are so new and the parts have not arrive to your country. You have searched from the internet and couldn't find one. In most electronic courses, you are taught to only use original numbers when comes to replace the power supply components especially the field effect transistor. Do you know that actually you can find a replacement that can not only replace the fet original number, the replacement will even work longer and sometimes better than the original! I will just take monitor power supply repair as an example.

Many times, i came across hundreds of different field effect transistor part number used in a monitor power supply. If i keep each different fet part number in a component's rack. I might need dozen of them and is a waste of money!

To solve this problem, i begin to do some research on each of the different fet. What i found in common is the volt, amp, watt and the ohms value. The results that i gathered made me found a universal number that fit into all 14" and 15" monitor switch mode power supplies. The field effect transistor is K1118 or 2SK1118 (JAPANESE CODE). Whatever 14" and 15" monitor came in for repair with complaint of power problems, I just replace the original fet (assuming the original fet blown) with K1118. This not only solve the power supply problems, it actually help me to save time and hassle finding the original value.

I do not know which electronic repair field you are in, but from the above explanation hope that you will find a universal number that fit into the  equipment that you repair-may be is a tv, radar, switch mode power supplies, oscilloscope, printers and etc. Compare each part number specification using the semiconductor replacement guide. As usual, if you could not find one from the book you can always search the internet.

Click here to learn testing electronic components like a Pro!!

Author By : Jestine Yong