View Single Post
Old 05-23-2022, 02:17 AM   #15
Maalobs
Member
 
Join Date: Jun 2016
City & State: Stockholm
My Country: Sweden
I'm a: Knowledge Seeker
Posts: 95
Default Re: Philips 70PUS7505/12 - Contrasts in image are echoed vertically upwards

Yes, this guy explains it to some extent in a two-part video:

I fixed a broken 4K 55 TV with TAPE | How to fix a TV with a blank screen
https://www.youtube.com/watch?v=pfrRhw7-ZII

Repair Hack Explained | How to Fix TV Horizontal Lines - Part 2
https://www.youtube.com/watch?v=SbGAkRgaZhs

He first measured all the ceramic SMD capacitors on the long, thin PCB to make sure there wasn't a short circuit on any of them.

He explains that the pins that are masked off on the ribben cable are clock signals on the horizontal plane, and in his case there appeared to be a short circuit in a subpixel on a single horizontal clock line on his panel after he tried reducing the block of masked off pins one by one.
The consequence of the masking is a possibly lower brightness on lines on the panel at the half where the masking is done.
He had to research a patent application to fully understand the technical implementation.
Maalobs is offline   Reply With Quote