T240 Monitor Backlighting Issue

[mucoast]

Re: T240 Monitor Backlighting Issue

I have a feeling that the wick might be a better choice. I can just plop the wick over the connection, heat it up and get most of it out.

However....ill probably just buy both to be safe.

Seriously, if this fixes the monitor, I am going to crack up laughing. Ill see if my friend can return his new monitor!

[Th3_uN1Qu3]

Re: T240 Monitor Backlighting Issue

Using a solder sucker or solder wick on each individual connection should do the trick. Once most of the solder is out of the way, apply lots of flux, then quickly run your soldering iron over all pins on one side until the solder is soft on all of them, remove that side from the board, then do the same for the other side.

[mucoast]

Re: T240 Monitor Backlighting Issue

So that was simple.

I purchased a replacement on ebay, but the sellers are all in Hong Kong/ China. Argh, gotta wait till almost oct. for the part to come in.


Also, one last question:

That transformer is a large part, much bigger than the caps I am used to replacing. Is there any information you can provide on getting this big ole' part out? I have a WES51 soldering station, is that sufficient?

[PlainBill]

Re: T240 Monitor Backlighting Issue

epic.


YELLOW POINTS: 935 Ohm
RED POINTS: .594 MOhm (WOW)

So one of the transformer secondaries opened up?

Yes. Looks like you will have a nice monitor for very little money.

PlainBill

[mucoast]

Re: T240 Monitor Backlighting Issue

epic.


YELLOW POINTS: 935 Ohm
RED POINTS: .594 MOhm (WOW)

So one of the transformer secondaries opened up?

[jetadm123]

Re: T240 Monitor Backlighting Issue

I believe your board has had problems with the the inverter transformer, T301. Hint: If you look on Ebay, there's at least 5 sellers selling replacement transformers. Try checking the secondaries of the transformer. With your meter set on resistance, place your probes across the yellow points and then across the red points. Difference between the two readings should be no more than 3%

[mucoast]

Re: T240 Monitor Backlighting Issue

Yep, verified. I hooked it up via DVI to my small server and, upon powering on, I saw the full screen.

A second or two later, the screen went dark. With the help of a trusty maglite I could see that the logon window was still displayed, just too dark to read without the light on it.

On a side note, I saw this: https://www.hobbymods.com/store/inde...ent-parts.html

Wondering what kinda caps they provide. Not a bad price, but wouldn't want to trade crap for more crap.

[jsog]

Re: T240 Monitor Backlighting Issue

Please verify if this is the common problem known as "two seconds to black". With a flashlight or other bright light at a flat angle, see if the screen is still showing an image after the backlight goes off.

TSTB can be caused by bad caps, bad inverter transformers, failing CCFL tubes, and other stuff. I'd check the inverter transformer first, mainly because I've got a board with an earlier version of that TM-10160 transformer laying on a shelf because of an open winding.

[mucoast]

Long time lurker, first time poster. Thanks in advance for any insight anyone might have!

One of my friends gave me his Samsung T240 display because it stopped working. I said I’d look into why this might be happening. He’s actually purchased a new monitor, so this is mostly just an experiment, but I’d sure like to find out why this problem is happening. I have been referencing these posts (https://www.badcaps.net/forum/showth...highlight=T240, https://www.badcaps.net/forum/showth...highlight=T240), but my problem appears a little different.

Symptoms:
The monitor turns on for a second or two, displaying the Samsung logo. However, shortly thereafter, the backlight turns off and the screen won’t display a picture. I can get similar behavior to occur when hitting the ‘source’ button. It doesn’t look like the backlight is totally out because it would ever light the panel, if that was the case. During the problem, the power light on the front is on.
Here is a youtube video of what is happening: http://youtu.be/7u-i_inT2RE



What I have done so far:

• Currently, I have the panel disassembled and have looked over the power supply. The panel is only 2-3 years old and was very well taken care of. The caps look to all be in very good shape.
• I have checked for shorts on U202 (see last picture, small 5-pin in middle), none.
• I have checked for shorts on the other IC, none.
• I WANT to check if T301 is okay, but don't know how to test. Can't find data sheet, either.

Component Conditions:

• No apparent bad caps (no bulging, leaking from top or bottom)
• No big burn marks on any components
• Slight browning of the PCB’s underside (trace side), though nothing looking too drastic