Samsung Syncmaster T220 2 seconds to black
 

I'm new in self-repair. However I will try to keep it short and simple.
Info:
Samsung Syncmaster T220
Modelcode: LS22TWHSUV/EN
Produced: 2009
Problem:
When pressing the power button it takes 3 seconds until a picture appear, then that picture disappear after 2 more seconds. Using a flashlight I can see movement on the monitor so should be a backlight turning off issue.
Slogan on the box:
"Design That Performs" (..badly because of cheap components)

Troubleshooting
Done so far:

• Found the power board and looked it over. Sadly can't see any bad caps or anything malicious. Took 7 pictures if you want to look with your expert eyes.

Questions:
Now, I'm trying to get my hands on the needed tools. But before I have them I would like to find out precisely what to do.
Ok, I tried to read the guide at http://www.badcaps.net/forum/showthread.php?t=10419

While the caps looks fine I guess i will have to check those as well, don't know if I can get hold of a ESR tester or know how to use it.

I think i understand the mosfets, there's only one (IC102) and will test that as soon as i get my hands on a multimeter. As far as I understand I set it to 200ohm and check if it below 30. The same with the fuse/picufuse, where it has to be below 1.0ohm.

Now the "Bad inverter transformer" troubleshooting is causing me trouble. I don't know what to do. It mentions 4 pins but I seem to have 9 pins on each transformer like this:
http://www.badcaps.net/forum/attachm...1&d=1374764047
Any comments on what I should do here?

These seem to be the most likely things to test before I go further down the guide. Any other things I should test?

Thanks in advance for any comments
/Carbonic

Re: Samsung Syncmaster T220 2 seconds to black
 

The green fuse next to one of the transformers ???

Re: Samsung Syncmaster T220 2 seconds to black
 

Yes, should I test it in any way besides what I mentioned in my original post?

Re: Samsung Syncmaster T220 2 seconds to black
 

If the fuse is good, then measure the resistance between A1 and A3 on each of the inverter transformers,the readings should be within 3-5% of each other..

Re: Samsung Syncmaster T220 2 seconds to black
 

Sorry for bumping an old thread, but were you ever able to fix this monitor?

I have the exact same issue with my Samsung T220, no capacitors show signs of bulging or leaking, and I have tried to replace two of the capacitors (those located in the middle bottom left corner above the screw hole) in this picture: http://badcaps.net/forum/attachment....3&d=1374764047

I have also tried to replace both inverter transformers, the TM-21240 ones, but with no luck. It's still exactly the same symptom. :crying:

The red power light comes on, the screen will turn on, and the screen comes on and shows the picture perfectly for 2 seconds before it goes black. I can see the picture if I use a flashlight.

In the last couple of months before the screen got like this, the top part of the screen would flicker erratically. It also was a little bit dimmer in this flickering part of the screen, this got worse with time until it got completely unusable with the 2 seconds to black symptom.

Any guidance would be appreciated. I have a multimeter which i can measure with if any of you can point out what to look for.

I feel like I can't give up on this now with this much effort put into it. Maybe I will try to replace the rest of the capacitors in spite of them seeming to be fine.

Kind regards,

krlle

Re: Samsung Syncmaster T220 2 seconds to black
 

could be a bad lamp ..think there is a way to force them on for testing only .

Re: Samsung Syncmaster T220 2 seconds to black
 

No I never fixed this error. Bought a non-samsung monitor and have moved along.

Re: Samsung Syncmaster T220 2 seconds to black
 

+1

Re: Samsung Syncmaster T220 2 seconds to black
 

Make a pair of test lamps:
http://www.badcaps.net/forum/showthread.php?t=19987

Re: Samsung Syncmaster T220 2 seconds to black
 

I'm also having this problem hope to find the answer soon

Re: Samsung Syncmaster T220 2 seconds to black
 

Hi, Ori!

Please check if the 2 mosfets under the board are the AF4502C.

Changing these would fix the monitor in most cases.

Re: Samsung Syncmaster T220 2 seconds to black
 

Hi Senndogg,
Are those the 2 rectangle 8 legged things? How do I check them?

I managed to get a new Power board off ebay unfortunately it was poorly packed and arrived broken (PCB snapped) but it might be salvageable for parts

Re: Samsung Syncmaster T220 2 seconds to black
 

Yes. Just check if "4502C"is written on them. In my experience, changing them has resolved issues with late 2000s Samsung monitors.
Desoldering and soldering is better achieved with hot air + solder gun.

Re: Samsung Syncmaster T220 2 seconds to black
 

Thank you I will get onto when I can :)

Re: Samsung Syncmaster T220 2 seconds to black
 

1. Replace lamps
2. Replace lamps with 12V LED stripe

Re: Samsung Syncmaster T220 2 seconds to black
 

Thank you I have seen the build for this, if it comes down to it yeah I think I will replace it with led strips hoping not to have to pull that part of the screen apart unless I really have to. :smile:


I looked at both the mosfets the numbers read
4525GEM on both the boards i have

Re: Samsung Syncmaster T220 2 seconds to black
 

I changed over the mosfets with the 2 off the new broken board but still no change. so it wasn't that, I also have tried it with the smaller controller board swapped for the new one and no change either so it isn't that. The inverters also seem to test ok.

Re: Samsung Syncmaster T220 2 seconds to black
 

https://www.instagram.com/p/CR2btsAMfPe/

the mosfets

Re: Samsung Syncmaster T220 2 seconds to black
 

try using something to power the backlights . there are plenty of ready made driver circuits available .

Re: Samsung Syncmaster T220 2 seconds to black
 

if the back lights come on for a few seconds at the start doesn't that mean they are working ?

Since my last post I have changed all the caps I could cept the big one, I changed the green fuse, I changed both the inverters, changed both the mosfets, I also tried a different logic board so that is also ruled out as faulty .... still the same doing more research atm