Samsung PS50A557S3F

[ukvince]

Been looking at this tv for a friend. It powers up, blue light is steady. and all voltages are present and correct but there's no picture. After much deliberation I knew that the problem must be either the y-sus or buffer or both... I had already checked all of the caps / mossfets etc on the x and y-sus boards but found no issues there but a more in-depth check of the y-sus (LJ92-01549A) found that 3 of the smd diodes are short. These are D5029 / D5030 and D5040. They all have the same markings which are K4 8G, which i believe are rectifier diodes.
I want to replace these just for the hell of it (before i buy a new board) but I can't find any info on them anywhere so if anyone can help and tell what the specs are for these diodes I would be grateful.

Here's a pic of the offending items...


Thanks in advance...

[Nick's Tvs]

Re: Samsung PS50A557S3F

Check them out of circuit first
I believe this is what you have but would definitely want a double confirmation on that. This is your K4

[ukvince]

Re: Samsung PS50A557S3F

I checked them out of circuit and they are fine....i get continuity across the pads that they sit on...back to head scratching...