Monitor LG Flatron W1934S 2 seconds then turned off

[neoxenon]

Re: Monitor LG Flatron W1934S 2 seconds then turned off

Actually I inverted the ccfl connectors and it works fine again !

[budm]

Re: Monitor LG Flatron W1934S 2 seconds then turned off

Just do the comparison readings of both HV windings, they should be about 3% of each other.

[ferrets6]

Re: Monitor LG Flatron W1934S 2 seconds then turned off

Put meter in Ohm mode (2K Ohms scale).
It sounds like you do not know how to use meter, correct?
BTW, you should start the new thread since your model does not match the original thread.

Well, I solved in another way.
I just reversed the transformer and tested the other two outputs and they works fine, so the problem is that component (is made up of "two" different transformer in one).

However, I know well how to use a meter. But I didn't know which kind of value could I measure

Thank you anyway for your kindness

[budm]

Re: Monitor LG Flatron W1934S 2 seconds then turned off

Put meter in Ohm mode (2K Ohms scale).
It sounds like you do not know how to use meter, correct?
BTW, you should start the new thread since your model does not match the original thread.

[ferrets6]

Re: Monitor LG Flatron W1934S 2 seconds then turned off

Hi everyone, my name is Federico.

I have an LG Flatron W2241S with the 2 seconds on-off problem.
Well, after some tests I have discovered the broken component, the one in the pic, that should be the inverter tranformer (?)

EBJ57534701
EEL-22D

One of the two secondary, the one inside the red circle, is broken.
Or well, I think so!
I have already desoldered it, so I can make all measurement needed to prove it is the bad guy.

The question is, what kind of measurement (with the multi-meter) should I try?

[tawfeek_mokhtar]

Re: Monitor LG Flatron W1934S 2 seconds then turned off

https://www.youtube.com/watch?v=l-Ge0qIlabI

[budm]

Re: Monitor LG Flatron W1934S 2 seconds then turned off

Burnt wires at the end of the lamps are common failure, also worn lamp with blackened ends are common failure mode. You should also recap the power supply-inverter board.
http://s807.photobucket.com/user/bud...?sort=3&page=1

[n3lka]

Re: Monitor LG Flatron W1934S 2 seconds then turned off

Just something to add about the W1934S displays. I was fortunate to bring three home from work that failed. What I found was for all three monitors, one set of lamps in each had gone bad or were intermittent. I was able to pull some bulbs out of a panel to test.

What tipped me off was a video on youtube. Looks like on of his lamp sets had a bad connections. My connections were good, the bulbs were just starting to go. Very burned up on the inside of the bulbs. It could be a sign of a poor connection there. I just didn't go as far as pulling the end off Since I had bulbs from the other displays to play with.

Here's the video link in case you haven't seen it. https://www.youtube.com/watch?v=l-Ge0qIlabI

[maxcap]

Re: Monitor LG Flatron W1934S 2 seconds then turned off

flatron w1946s - bf

w1946sw

manufactured 2010

[maxcap]

Re: Monitor LG Flatron W1934S 2 seconds then turned off

See pic
Set your meter on ohms 2000
NO power to the board test S1 to S2 and post the result.

Resistance should not continue to rise - is battery good in meter

my reading is 0.845 k ohm

is that ok?

[maxcap]

Re: Monitor LG Flatron W1934S 2 seconds then turned off

S1 to S2 760 Ohm, resistance is rising on pins on another side.

my reading is 0.845 k ohm

is that ok?

[maxcap]

Re: Monitor LG Flatron W1934S 2 seconds then turned off

Sorry to drudge up an old thread but this worked like a charm, just ground the 3rd pin on IC501 (which took me forever to find) and the backlight will stay on when ever the monitor is on fixing the 2 second black screen (at least in my case).

Hi im looking for IC501? can ypo please point it out on the board?

[mulanputrovic]

Re: Monitor LG Flatron W1934S 2 seconds then turned off

760 may be ok - cant quickly find the specs for it - have you looked?
At least its not open or shorted.

When you say you tried a laptop tube do you mean just on its own?
If you just use a single tube you will almost always get 2sec to black.

You need to substitute the lapstop tube first for one of the panel tubes leaving the other panel tube plugged in then do the same for the second panel tube plugging the first panel tube back in.

Thanks!!! Thats it.

Connection on one ccfl was lose so i soldered it, now everything work as it should.

[selldoor]

Re: Monitor LG Flatron W1934S 2 seconds then turned off

760 may be ok - cant quickly find the specs for it - have you looked?
At least its not open or shorted.

When you say you tried a laptop tube do you mean just on its own?
If you just use a single tube you will almost always get 2sec to black.

You need to substitute the lapstop tube first for one of the panel tubes leaving the other panel tube plugged in then do the same for the second panel tube plugging the first panel tube back in.

[mulanputrovic]

Re: Monitor LG Flatron W1934S 2 seconds then turned off

S1 to S2 760 Ohm, resistance is rising on pins on another side.

[selldoor]

Re: Monitor LG Flatron W1934S 2 seconds then turned off

See pic
Set your meter on ohms 2000
NO power to the board test S1 to S2 and post the result.

Resistance should not continue to rise - is battery good in meter

[mulanputrovic]

Re: Monitor LG Flatron W1934S 2 seconds then turned off

I have tried measuring resistance between pins but i cant get fixed reading, its increasing constantly. Should i desolder it first?

[mulanputrovic]

Re: Monitor LG Flatron W1934S 2 seconds then turned off

Whats the part number of the invertor transformer? maybe next step test the primary and secondary readings on it.

Thanks for the reply.

Is it smaller one near ccfl connectors?

IT-007
0572 LC UK10 S

It has 2 pins on one side and 7 on another one. How can i test it?

[vinceroger69]

Re: Monitor LG Flatron W1934S 2 seconds then turned off

Whats the part number of the invertor transformer? maybe next step test the primary and secondary readings on it.

[mulanputrovic]

Re: Monitor LG Flatron W1934S 2 seconds then turned off

Hello.

I am asking for help because i have same problem with similar monitor LG W1946s-bf.

Power LED stays on and light goes out after 2 sec.

I have tried following:
- replaced all the caps
- checked diodes with multimeter
- tried another ccfl from laptop screen ( 2 sec problem again)

What should i try next?

Here are the pictures of the monitor board.