I have a bunch of Samsung TVs with bad backlights. They all have over 50-90% bad LEDs and need full replacements. Unlike LG models, the backlight does not shut down when a problem is detected and it appears the shorts may damage the power supply.
I got strips from Aliexpress Rzconne brand strips for one UN46H203AF, did the replacement and 2 strips failed after 3 days even with backlight level reduced. The seller shipped me replacements and when I installed them, the backlights were flickering powered with the power supply (main cable disconnected, tested fine with LED tester). I got hold of another TV the same model with bad backlights as well and tried that power supply on the original TV and the backlights failed to come on at all. I ordered a used power supply on ebay and that power supply appears to work properly.
On the flickering power supply and the no backlight power supply, the area around D9801 and Q9801 are noticeable darkened by heat. Part number is BN44-00771A. Checking D9801 in circuit, the no backlight PS measures 1V in reverse direction vs OL on the working PS. Diodes on all 3 show about 0.5V drop the forward direction.
Will investigate a bit further but a schematic would help.
I got strips from Aliexpress Rzconne brand strips for one UN46H203AF, did the replacement and 2 strips failed after 3 days even with backlight level reduced. The seller shipped me replacements and when I installed them, the backlights were flickering powered with the power supply (main cable disconnected, tested fine with LED tester). I got hold of another TV the same model with bad backlights as well and tried that power supply on the original TV and the backlights failed to come on at all. I ordered a used power supply on ebay and that power supply appears to work properly.
On the flickering power supply and the no backlight power supply, the area around D9801 and Q9801 are noticeable darkened by heat. Part number is BN44-00771A. Checking D9801 in circuit, the no backlight PS measures 1V in reverse direction vs OL on the working PS. Diodes on all 3 show about 0.5V drop the forward direction.
Will investigate a bit further but a schematic would help.
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