Burning machine method to repair Konka LED32F1160CF three no cases - Home Appliances

MOS power IC full range

Filter 18.432M

A few days ago, I got a faulty Konka LED32CF1160CF TV. It wasn't working at all. I took it apart and found out that it uses a 3-in-1 motherboard with a specific board number. The first thing I did was check the main components using a VC9808+ multimeter. The fuse was intact, and the 300V filter capacitor had about 30V left. The resistance from the S pole of the power switch tube to ground looked normal. But when I checked the secondary side of the switching power supply, I noticed that the 12V rectifier VDW963 MBR20100 was shorted in both directions. That’s not good — this type of diode is known for being fragile under high current stress.

I decided to replace the VDW963 and tested it with a pointer meter. To my relief, it was fine. So the problem must be somewhere else — likely in the 12V filter or its connected loads. The 12V line goes to several places: the power supply switch V8019435, the backlight booster N701OZ9902C, the DC-DC converter N803AP3502E, and the power amplifier block N202PAM8006A.

Since I didn’t have much equipment on hand, I used what I could. I connected a 3.3V power source (capable of 6A) to the negative end of VDW963. After just two touches, I saw blue smoke coming from the N803 section. That’s when I knew something was wrong. I carefully touched the smoldering area and found that C898 was bad. I replaced it with a new 10UF capacitor. Also, to be safe, I replaced the inductor L805 near the 12V input of N803 to prevent any high-frequency interference issues.

After replacing the parts, I powered the TV back on. To my relief, everything worked perfectly — the picture and sound were clear. I wrote the repair date on the TV, closed the back cover, and sent it back to the user. It felt great to fix it without too much hassle. Sometimes, even with limited tools, you can still make a big difference.