Baier 27" lcd screen keeps turning on and off

[maz]

Hi All i have a Baier LCD tv and the screen keeps turning on and off it has two input boards, one with scart sockets and other one is with VGA and it happen with both inputs i don't know if it is the inverter board or power board could some kindly guide me Thanks.

[tom66]

Re: Baier 27" lcd screen keeps turning on and off

If you have the TV on in a dark room, does the screen still glow when it goes off?

[maz]

Re: Baier 27" lcd screen keeps turning on and off

Thanks Tom,

I think it does not it goes blank i am not 100%, but lets say it does then what does it means.

[tom66]

Re: Baier 27" lcd screen keeps turning on and off

Thanks Tom,

I think it does not it goes blank i am not 100%, but lets say it does then what does it means.

It's a crucial difference in locating where the fault is. An LCD TV uses a back light to illuminate the screen. The LCD's pixels can let through a variable amount of light to create an image.

If the screen is lit, but the LCD is blocking light - it's a T-con/Main/PSU problem. The T-con drives the pixels. The main board processes the video and audio. The PSU provides power to everything.

If the screen is not lit (and the LCD -may- be working) - it's an Inverter/PSU problem. The inverter lights the screen.

Baier is probably another Vestel crap badged brand, these have common problems with the PSU dropping out power to inverter.

Can you post some pictures of your TV's guts?

[maz]

Re: Baier 27" lcd screen keeps turning on and off

I bought it as faulty to experiment the sound stays on just the picture goes on and off.

[selldoor]

Re: Baier 27" lcd screen keeps turning on and off

Hi - sorry about that - I had to go out - nothing worse than an unrelated issue
In the middle of a thread.- Anyway
Welcome to the forum-
We can help a lot more if you please post good clear pictures of the whole chassis, and then pictures of each board, front and back and close up of connectors, (max resolution 2000x2000 and 2MB) using the manage attachments button, which is found by clicking "go advanced" under quick reply.

Please do not post inline and offsite as they slow down the loading of pages.

Examples of what is needed
https://www.badcaps.net/forum/attach...1&d=1290283049

https://www.badcaps.net/forum/attach...7&d=1280167246

It will be useful if you can say a bit about yourself - skills tools etc.
I see Tom has asked for pictures thought I'd do my usual greeting which
helps you load them

Please can you also give the model number of the tv

[tom66]

Re: Baier 27" lcd screen keeps turning on and off

I bought it as faulty to experiment the sound stays on just the picture goes on and off.

Please do the test at the nearest opportunity so the fault can be traced to the backlight or video section. And post some clear photos of the boards inside. It is likely an easy fix.

[maz]

Re: Baier 27" lcd screen keeps turning on and off

Hi Tom and Selldoor,

i have attached three pictures. the invertor board in between these board and lcd i will try to get the picture of that in the good light.

[selldoor]

Re: Baier 27" lcd screen keeps turning on and off

Pictures are not really clear enough for troubleshooting - we need to be able to read the small numbers on the boards. Have you checked the caps for swollen/leaky. The two on the bottom left hand corner of your pic 1 appear to look a bit swollen in Pic 2. Having said that Tom may recognize the boards. If you can do his glow in a dark room test and give us the tv model number off the label on the case back and also the part numbers off the boards- in the last pic the No is like L0*231E20 *

[maz]

Re: Baier 27" lcd screen keeps turning on and off

I think model no is Baier LCD27, plase look at the attached picture. i will try to get more clear picture.

[tom66]

Re: Baier 27" lcd screen keeps turning on and off

Do you have a multimeter?

[maz]

Re: Baier 27" lcd screen keeps turning on and off

Yes i do

[maz]

Re: Baier 27" lcd screen keeps turning on and off

Taken some more pictures they might help, the screen comes on by changing the channel + - button and goes off after few seconds used hair dryer and it stayed on for more longer time and did not switch.

[selldoor]

Re: Baier 27" lcd screen keeps turning on and off

Have you got a source connected -A dvd is best if you have one then you can just leave it running to provide a picture and sound source. When its on is there an actual picture
and is there sound. How long does it stay on.
When it turns itself off what does the power light do.
Does it come back on by itself? how long is it off for?

What did you use the hair dryer on?

Pictures are doing my head in!! Pic 5 Right hand corner a row of little caps 2 and 4 look to have something on the end - Do they? can you do an infocus pic of the row of5

[maz]

Re: Baier 27" lcd screen keeps turning on and off

got more info the back goes off with the picture, does that mean it is to do with inverter board? i have taken picture of dvd as selldoor said also included side view of back light on when screen is on and also with back light off.

[maz]

Re: Baier 27" lcd screen keeps turning on and off

The power light is red first then it goes orange for few seconds and then green and it stays green even with screen off on effect on green when screen is on or off.
i used hair dryer on power board and also on main board where wires are going to the inverter board. then is did not go off. all the caps look good no leakage nothing i can see sorry for bad quality pictures will try to get batter camera tomorrow. it takes like 15 20 minutes to come on and might stay on for a while no dry solder joints under power board.

[selldoor]

Re: Baier 27" lcd screen keeps turning on and off

When it appears to have gone off, as the power light stays on
If you shine a torch on to the panel can you see a faint image of the video that is playing

The heading says it turns on and off- when it turns off does it come back on by itself
or do you have to switch it off then back on.

You need to narrow down the hairdryer heating area to pinpoint which board it makes it work on- it will have to cool between tests.

[maz]

Re: Baier 27" lcd screen keeps turning on and off

I will try a torch trick, not sure if it comes on it self but if you use the ch + - buttons the screen comes on and goes off and if it comes on and circuit is warm then it stays on.

[maz]

Re: Baier 27" lcd screen keeps turning on and off

Selldoor half of your message is not showing up in forum but i have just read it in my email like you asked me about the speakers plugged in, i can't see that part in here at the forum but it is in my email pardon me i am new to the forum. The sound is there when they are plugged in, I have fixed few LCD monitors with the help of you guys at badcaps forum and i have multimeter magnifying glass and some theoretical knowledge of electronics.

[selldoor]

Re: Baier 27" lcd screen keeps turning on and off

Hi - sorry - i was getting tired and mixed you up with another thread I was
looking at. I also started my last post after the one with the pictures but before you answered the questions so I edited a lot of it out as it was no longer relevant. I also kept on asking about sound then noticed in post 3 you said it was on all the time so I edited that out as well. I didnt know that when post is made it emails it - I must have been confusing people for months
I will have to be more careful.