How to test KIA78R09PI

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

Read More

ViewSonic LCD Monitor Went Off After Few Minutes

Dear sir,
One of the LCD ViewSonic VA1931WA-2, complaint was it went off after 3 to 5 minutes. I connected the VGA cable and power on, Viewsonic logo appeared but after 5 minutes power went off. The power LED also went off. I pressed the power switch but i didn’t work, I switched off the main power and connect again display will come, but after 3 to 4 minutes power went off again.

Read More

New Elditest High Voltage Oscilloscope Probes

high voltage probes

Recently Cal Test Electronics introduced a new line of Elditest brand High Voltage Oscilloscope Probes. The line includes the following models:

  • CT2982B
  • CT4024
  • CT4025
  • CT4026
  • CT4028

The new Elditest probes are high voltage divider probes for use with both digital and analog oscilloscopes. If your job requires you to check on high voltage components such as the flyback transformer and etc then you need this tester. Normal digital and analog multimeter would not be able to measure the high voltage where it can reach more than 20,000 Vdc. Below is the photo and video of the testers: Read More

About IC Programmer In the Market

For the past weeks I’d been receiving a common question about IC programmer. The question was which one is the best and which programmer can be used to program my ICs? Actually there is no best programer in the market because programmers coming out to the market every now and then with better features and etc. Ok here is the answer for those who wanted to buy a programmer:

1) Make sure that programmer could support the IC part number that you want to program. Most of the programmer website will list out the IC part numbers. If the programmer could program many types of ICs( MCU, PIC, EEPROM, FLASH ROM and etc) then it will be good

Read More

About CRT Deflection Yoke Coils

Some days ago my Samsung 21″ CRT Flat televisions Deflection Yoke Coil were burnt. I already replaced it(near by same type but not same) but the horizontal alignment of picture is not straight it looks some curve. Can you help to solve this problem.
Reply :
It is very difficult to adjust the CRT Deflection Yoke alignment once it is removed because all the alignment were done in factory by using machine. Furthermore you have used the deflection of not the same spec. This means you may have to take extra time to play around with the adjustment till you get the best picture. The yoke coil alignment is very sensitive and a slight adjustment will cause the focus out and mis-convergence.

Read More