Riddled TV Repair Forum

sn0wer · Joined: 15 Oct 2017 Posts: 4

Hello everyone,

I had some trouble lately with an LCD screen https://imgur.com/gallery/fV2is. Image became white all the sudden.

I have several questions :

A/ I've read that it's probably the TCON board's fault, is it plausible ?

B/ In the affirmative, can I fix it myself ? Where should I start to look ?

For those who are interested, here is the service manual (https://elektrotanya.com/philips_42pfl5603d.pdf/download.html).

Thank you.

Google

JTS1957 · Joined: 21 Jan 2009 Posts: 2395 Location: Far, Far Away

Audio or NO Audio?
Are ALL OSD's washed out or normal, you only show one example, which seems washed out?

sn0wer · Joined: 15 Oct 2017 Posts: 4

Hello JTS1957. Thank you for your response.

JTS1957 · Joined: 21 Jan 2009 Posts: 2395 Location: Far, Far Away

So your complaint is more consistent with 'washed out' rather than 'white.'

Since OSD & video are affected equally ...
A Tcon board is cheaper and is more easily obtained than a panel which is the second choice.

sn0wer · Joined: 15 Oct 2017 Posts: 4

Just a quick followup for anyone having the same problem.

I found an interesting video (https://www.youtube.com/watch?v=eZZwb35ou_Y) to detect problems with gamma channels (generated here with AS15F chip). There are testing points (called VGMA1, VGMA2, ...) on the TCON (called T420HW01 V2) that you can measure (see the video) to see if the gamme channels are generated correctly. Lucky for me the voltage points weren't coherent (should increase/decrease linearly) + the IC was too hot. I'm going to change it with a rework station and see what happens.

Google