LG Flatron

[rpj7]

Re: LG Flatron

I have been following this thread whilst trying to sort out a Flatron W2246S of my own, I keep an eye out for scrap monitors at work and got 2 with a similar 2 faults:
1.Turned on shows the LG badge, turn off, turns on again briefly then dies.
2.Turns on and squeals like very high frequency arcing and worked for a while, then it would turned on for 2 seconds and turn off.
So it seems like 1 was dead and the other dying.

Found they both had 1 bad CFL bulb each. changed a tube over and I now have a working 24 in monitor and a box of spare bits !

Once I got it working I did swap the PSU & video boards over to prove they were OK. So I have a spare board (Although I cracked a screen being clumsy after I had stripped it down for the bulb) anyone is welcome the boards for the cost of the postage - I will hang onto it for a while an no doubt get rid of it just before it would come in useful!

(spare board with the now working screen)

[selldoor]

Re: LG Flatron

While you wait perhaps make up a couple of these unless you have any spare bulbs
another monitor dead laptop.
https://www.badcaps.net/forum/showth...er+testing+cfl

[polo-mk3]

Re: LG Flatron

Cheers guys,

I will re-solder the above components give it a try and get back to you. then I will order the new caps and see what happens

Morning,

I re-soldered the components from above and its still doing the same. So I have just ordered some Panasonic caps.

[polo-mk3]

Re: LG Flatron

Cheers guys,

I will re-solder the above components give it a try and get back to you. then I will order the new caps and see what happens

[selldoor]

Re: LG Flatron

Yes pictures are very good only thing is we ask that they are posted on site
( maybe you struggled because of the original size)
I have re loaded them so that others can see what the remarks refer to when
/if they are removed from the offsite.

As well as the above resoldering is looks like C205 C207 C209 C203 have been
moved or replaced at some point anyway if it gets back to working, there are so few caps you should replace all except the BIG one with good make new ones. Panasonic FR FM or FC or similar

[stj]

Re: LG Flatron

resolder:
D203
T101
U302

they all have cracked soldering

[polo-mk3]

Re: LG Flatron

Really need good clear pictures of your boards front and back

Any good?

http://www.cdgold.co.uk/polo-mk3/rep...420_165617.jpg

https://www.cdgold.co.uk/polo-mk3/re...420_165552.jpg

[selldoor]

Re: LG Flatron

Really need good clear pictures of your boards front and back

[polo-mk3]

Re: LG Flatron

All you can do is test the transformer as above. post11.
It is unlikely the transformer would work(even if it physically fits) you would need to ask the vendor.
Do the lamps flash at all - what does the power led do.
Can you see an very dark image on screen.
Did you own the monitor or buy in to fix if owned did it have any other symptoms
fllickering/ pink tinge/ sometimes not come on etc.

Hi Selldoor,

I own the monitor, it started to look like the backlight was fluctuating (if thats the right word) like a random ripple effect but only in the backlight.

But then today it started turning itself off and the power led would stay lit. If i just turned it on and off would put the screen back but now it lasts about 5 to 10 secs then off again.

Yes i can still see the image in the background. Caps look good but not tested them but there is a squealing sound when the backlight comes on.

Just uploaded this video to youtube if it helps : https://www.youtube.com/watch?v=xZfNvBGiYZg

When its powered on you can see the LG logo for a few sec's

[selldoor]

Re: LG Flatron

All you can do is test the transformer as above. post11.
It is unlikely the transformer would work(even if it physically fits) you would need to ask the vendor.
Do the lamps flash at all - what does the power led do.
Can you see an very dark image on screen.
Did you own the monitor or buy in to fix if owned did it have any other symptoms
fllickering/ pink tinge/ sometimes not come on etc.

[polo-mk3]

Re: LG Flatron

Hi Guys,

I know this thread is old but im having the exact same problem with the same model monitor.

Caps look fine and the noise is coming from the inverter transformer (this is marked up with : IT-007 -EBJ55945505 -DD 1023)

Whats the best way to test the transformer and would this work if its faulty?

http://lcdinverter.co.uk/index.php?m...roducts_id=469

Thanks

Ben

[selldoor]

Re: LG Flatron

You can test the inverter transformer - board doesnt need powered on for that.
Post a pict of the boards when in the frame - perhaps there is a way?

Most people can do the voltage tests with the boards connected but out of the frame
- you can separate them with card to stop them touching each other.

[Macedopt]

Re: LG Flatron

hi,

Sry for the delay, didnt have the opurtunity to come here, regarding your questions i try to measure it powered on bunt cant acess the componets the build on this screen basicaly dont let you test it powered on, i have recaped the board with low esr caps and dint solve the problem, i dindt recap the 450v one, i still can hear a gruning sound coming from the inverter section, il try buy the inverter and then see if it solves.

il keep you guys update, ty for the link to ebay seller might buy from him.

thanks a lot

regards

[selldoor]

Re: LG Flatron

Hope you are going to use good quality low esr caps.
We do not replace ceramic caps as a matter of course - only when proven bad.

Questions

Basic tests - with it all connected up and power to the set but switched off
Meter on 600 vDC CAREFULLY measure across the Legs on the BIG CAP.

Switch the power on then do the test again.

Next meter on VDC 200 list the voltages you get on the connector that goes from the power supply to the main board along with what it says they should be.
Example

PIN 1 12v 11.25v
PIN2 gnd 0.00
PIN3 pson 3.37v
*******************************************
Anyway you can still test the secondary - Power to board off set you meter on ohms 2000 and measure S1 to S2 in the pic ( Do NOT try to measure the voltage on these pins)
**********************************************
Do you have any spare bulbs - old monitor or laptop. if not can you make a test bulb?
***********************************************
Are you doing the voltage tests? - before you replace caps
then any improvement can be seen

[Macedopt]

Re: LG Flatron

Hi selldoor


Sry for my late reply have been busy and could not reply erlier, yes my tranformer is the IT-007 il search it on ebay and try talking to the seller.

I still have not rrecap the board, will do it on weekend, if it doesnt work il try buy a coil and capacitator tester, when you guys recap do you recap the ceramic caps too or only the electrolitics?

Thank you so much for the replys i wish someday i can return the favor.

Selldoor can you be more specific in the question you need me to answer? i have read this 2 times and cant find what questions you are refering to.

ty mate best regards

[selldoor]

Re: LG Flatron

Hi guys

ty for all the info, il try if a full recap will solve the problem, and then post the results, just one more quick question when testing the transformer what results should i expect.

Sry for all the stupid questions.

Regards

I dont think we know if you go to
http://lcdparts.net/T.aspx and pick a few - click on "Buy it now"
It doesnt buy it and if you scroll down a bit it says what the secondary winding measures - Try a few and you will see how they differ.
Unfortunately couldnt see one of yours - think its a IT-007 ? did find one in ebay though - you could try querying the seller?

Can you answer any previous questions you have not answered.

[Macedopt]

Re: LG Flatron

Hi guys

ty for all the info, il try if a full recap will solve the problem, and then post the results, just one more quick question when testing the transformer what results should i expect.

Sry for all the stupid questions.

Regards

[smason]

Re: LG Flatron

I am just a hobbyist so I dont bother testing caps - if I am fixing something I usually just replace all except Big ones.

I agree, even though I have the gear to test 'em. That goes against my normal methods, where I want to find the exact cause, and not "shotgun" a problem, but with monitors, I almost always recap.

I've seen so many obviously failed caps, if the monitor has the same crap brand (Samxon GF etc) I'll replace them all.
Sometimes I'll measure them, and I'm often stunned at just how bad they are.
The only thing that really ticks me off is recapping a monitor only to find it now works, but has an irreperable problem like a cracked screen that I didn't notice, or unavailable transformers. I'll keep the boards and recycle the rest in those rare cases.

[selldoor]

Re: LG Flatron

I am just a hobbyist so I dont bother testing caps - if I am fixing something I usually just replace all except Big ones. You can find some tests on line or possibly even on here, but I dont think they prove much.

I thought about the Inverter transformer and even got a picture ready but unless we can find data for it we dont know if the test is good or bad.
Usually there are two transformers to compare.

Anyway you can still test the secondary - Power to board off set you meter on ohms 2000 and measure S1 to S2 in the pic ( Do NOT try to measure the voltage on these pins)

Do you have any spare bulbs - old monitor or laptop. if not can you make a test bulb?

https://www.badcaps.net/forum/showth...ght=test+lamps

Pictures are a lot better - thanks

Are you doing the voltage tests? - before you replace caps
then any improvement can be seen

[Macedopt]

Re: LG Flatron

Hi,

Here are more pics without flash as you said, il try replace all the capacitors, from you experience you dnt think its the transformer right, im talking about the square where the ccfls conect, the photo nº 99.

By measuaring the capacitators what values i should expect? or i need only to see if they are charging and discharging?

thank you

regards