Konka LC-TM2620 LCD TV black screen - appliance repair

Electronic scale crystal oscillator 3.2*2.5mm 3225 16M (16.000MHZ) 12PF 10PPM 20PPM 30PPM

Heng Jiaxing AO3401

Brand AVX TPSE226M035R0125 Low impedance tantalum capacitor AVX 22

Konka LC-TM2620 LCD TV is experiencing a black screen issue. First, I checked the backlight power supply and found it to be normal. Then I tested PBACK, which was at 0V, indicating a possible problem with the motherboard. Next, I examined the motherboard's CPU for DC-DC conversion, specifically checking U802. Here’s a photo of U802:
When measuring the resistance from pin 3 of U802 to ground, it showed 0 ohms. This suggested a short circuit in VD802. After replacing VD802, the screen turned on for about 15 minutes before going dark again.
I then rechecked C814 and C850, and they appeared to be in good condition. After testing C813, everything seemed to function normally. Further diagnostics are needed to determine if there are other faulty components or if the replacement part needs to be verified.