LCD monitor troubleshoot (flatron LG W2246)

[Libas]

Hi there,

could somebody help me with diagnostic of this faulty LCD monitor?

After power plugged in screen turns on for approx 1 second, then turns off....after few seconds turns on again for 1 second and turns off again forever.

Any advices what could cause such a symptomps?

I will also very apreciate any study materials how to diagnose LCD monitors in general.

[fzabkar]

It sounds like a backlight problem.

Service manual:
https://elektrotanya.com/lg_w2246s.pdf/download.html

[RayRay]

There are different possibilties, such as a shorted power button, bad power board or t-con board.
How to proceed really depends on your level of knowledge & equipment. Of course most faults are fixable with the right knowhow, but if you don't wanna go that route, each board has a part number, which you can look up to find a replacement.

[Libas]

Backlight and also picture looks good. Of course Im interested in troubleshoot and board repair...thats why Im here...to learn something new
I have equipment available...just dont have enough experience with LCD monitors yet.

[RayRay]

Well, I'd suggest you start by measuring the voltages from the power board (where the connectors go to).
You could also do a 50/50 with the flat cables going from the t-con board to the upper (left/right) lcd controller boards (and by that, I mean disconnect one of em, and see it anything changes, try each standalone without the other one connected)

[Libas]

It looks to me like power board and also t-con board works "fine"....there is just some fault which shuts if off nearly immediately

[Libas]

all electrolytic caps look OK...no bulging visible

[RayRay]

It looks to me like power board and also t-con board works "fine"....there is just some fault which shuts if off nearly immediately

I see a huge problem here! You're making quite a bit of presumptions and showing major lack of interest in actually figuring out the problem. So given this, your only repair options are to:

1. Verify that the backlight is good by using an lcd backlight tester (personally, I think it's unlikely to be the case, but those testers are quite affordable)

2. Try sourcing replacement power/t-con boards by their part number (can be either on a sticker or printed directly on em)

If you're not willing to do these things, then just forget about it.
I'm being practical.

[p.larner]

have you shone a torch as the screen to see if its not just a backlight issue?.

[Libas]

have you shone a torch as the screen to see if its not just a backlight issue?.

Yes...very good comment! I totally forgot such a basic check.

Picture is OK...just backlight switches off.

Thank you!

[RayRay]

have you shone a torch as the screen to see if its not just a backlight issue?.

Yes...very good comment! I totally forgot such a basic check.

Picture is OK...just backlight switches off.

Thank you!

Keep in mind that this doesn't necessarily mean that there's a backlight issue (you'd have to use a backlight tester to know for sure though). It could still be an issue with the power board or t-con

[Libas]

problem solved...one CCFL tube had broken connection.

As I saw in the internet its common fault. Details for example here in this video:
HOW TO FIX HP LCD, monitor turns off after 3 seconds (common repair)