sir, May I know how to test “KIA78R09PI”. There is not output voltage
from the mentioned ic on the PCB of TV. and I can’t understand to
test it. please show some ideas to test it. hope lots of help comes.



This is a 4 pins Voltage Regulator IC. It has an additional control pin and the signal usually coming from MCU IC to trigger the IC so that there will be output. If there is no signal to the control pin this means there will be no output. The first thing to check, the IC must have DC input first. You need to locate the datasheet in order find out the control pin. If there is an On signal (usually few volts) to the control pin and if the input dc voltage is presence and no output voltage then direct replace the IC. If the load has something shorted, it can also cause the output line voltage to drop. This also means you need to lift up the IC output pin and test. If still no output voltage then the IC indeed is faulty and need replacement



Jestine Yong works as an Electronics Repair Lecturer in Kuala Lumpur Malaysia and his training website is You can check out his repair blog at

2 comments on “How to test KIA78R09PI

  1. Thank you so much my boss for all the assistance we’ve been getting on your website. They all made me a better technician.
    Pls my enquiry is about an Epson LCD Projector Model:EMP-61. When its powered it beeps and begins to boot but after about a minute and fifteen seconds, it fails to boot-up but illuminates the red lamp indicator. I have tested the lamp and its OK comparing with another lamp I have. Please what could be the problem? Thanks in anticipation.

    1. admin says:

      Hi Chidi,

      Have you checked that the output voltages from the power supply good and stable?


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