TCL LCD TV L46P21FBDE flower screen fault repair experience sharing - Home Appliances

I don't underestimate the impact of a tiny sesame seed — even a small mistake can lead to hundreds of issues. Sharing my experience repairing a TCL LCD TV model L46P21FBDE with a flower screen issue. The board number is 40-206P11-MAB2XG, and the mainboard is V8-M206P10-LFIV083. The customer mentioned that someone else had disassembled the unit and claimed that a large aluminum block was broken and some parts were missing. I assumed it might refer to the big chip under the heatsink. I discussed the price with the customer and asked them to wait for a call. When I turned on the TV, the red flower screen appeared, then turned green after about half a minute, and the image came back, but there was a shadow.
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First, I checked the screen cable, but pressing or scrubbing didn’t help. I suspected the logic board, but the voltage levels looked normal. I tried to test the screen, but couldn’t see clearly due to the limited screen view. I removed the screen board and found no issues. So, the problem must be on the motherboard. [attach]612935[/attach] [attach]612940[/attach][attach]612941[/attach]
I decided to reprogram the board. I read the backup data, but when writing, it failed to unlock. I had to give up on that attempt. I also measured the key voltages on the mainboard, but found nothing unusual. I was stuck.
In the evening, I reviewed the situation again. This board was worth more than $300–$400. After searching online, many people said it might be a frequency multiplier issue. Subconsciously, I felt something was wrong with the temperature. When I touched one of the components, the flower screen color changed! I was excited — this was the issue. It was either a desoldered component or a poor solder joint. I checked and found that R133 and R136, which are 47-ohm resistors, had become several mega-ohms. I replaced them immediately, and the power test worked perfectly!
I also uploaded and shared the program data from the board, hoping it could help others.
Backup for TCL L46P21FBDE board number 40206P11MAB2XG with AU screen T460HW04 V.1 (MST_EXT_SPI #ISP_2017092.rar).

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