Samsung PS-50C62HX/XEE. 50 inch plasma. Sound but no picture.

[Eskil]

I got this 50 inch plasma flat screen from an aqauintance who couldnt make it work. Now if I am able to fix it, I get to keep it! It sounds like it turns on fine, but the picture never shows up.

I am stumped. I have changed the bad fuses and tried looking for the most usual problems all around the net, but to no avail. This is what I have so far:



Boards I have checked:


50''HD W2 PLUS Y-MAIN (2L)

- Changed fuse F5700 (green, soldered) that was dead, with a glass tube fuse.
- Checked 680 uF Capacitor, C5709, with multimeter. Capacity seems fine. I read it usually dies first.
- The green LED (LED5800) turns on when the TV boots up.

50''HD W2A GVE YB (UP) and 50''W2A GVE YB (LOW)
- No visible damage. I did what this guy did in this video, and I got beeping on the first socket on the (UP) board. Not sure what to make of it.

50''HD W2 PLUS X-MAIN(2L)

- It gives off a buzzing sound. Not sure if its the coils or something else.
- Changed one of two green fuses (F4800) with a glass tube fuse. It was dead.


I am far from an electronics expert, and I just know the absolute basics. Im a marine engineer, and am not used to working on stuff that isnt power plant sized, so I could use some advice on what I do now. Any advice at all will be highly appreciated.

[tw2005]

Re: Samsung PS-50C62HX/XEE. 50 inch plasma. Sound but no picture.

I got this 50 inch plasma flat screen from an aqauintance who couldnt make it work. Now if I am able to fix it, I get to keep it! It sounds like it turns on fine, but the picture never shows up.

I am stumped. I have changed the bad fuses and tried looking for the most usual problems all around the net, but to no avail. This is what I have so far:



Boards I have checked:


50''HD W2 PLUS Y-MAIN (2L)

- Changed fuse F5700 (green, soldered) that was dead, with a glass tube fuse.
- Checked 680 uF Capacitor, C5709, with multimeter. Capacity seems fine. I read it usually dies first.
- The green LED (LED5800) turns on when the TV boots up.

50''HD W2A GVE YB (UP) and 50''W2A GVE YB (LOW)
- No visible damage. I did what this guy did in this video, and I got beeping on the first socket on the (UP) board. Not sure what to make of it.

50''HD W2 PLUS X-MAIN(2L)

- It gives off a buzzing sound. Not sure if its the coils or something else.
- Changed one of two green fuses (F4800) with a glass tube fuse. It was dead.


I am far from an electronics expert, and I just know the absolute basics. Im a marine engineer, and am not used to working on stuff that isnt power plant sized, so I could use some advice on what I do now. Any advice at all will be highly appreciated.

when you say fuse was dead, are you saying open cct / blown?

The green LED is your clue. The ymain has a fault and with these 99.9% of the time it will be a shorted out upper buffer board and blown ymain.

Check these and see if shorted, 88n30W , 2SK2837, B20NK50Z . they're around and on that lower heatsink closest to the buffer boards in your photo

[Eskil]

Re: Samsung PS-50C62HX/XEE. 50 inch plasma. Sound but no picture.

With dead fuse, I meant it was "open". I tested them with the beeper on a multimeter and the "dead" ones didnt beep, making me believe that they were blown.

I will test the transistors as you say and report back here.

What can be done if the upper buffer board is shorted? I assume just buy a new one?

[tw2005]

Re: Samsung PS-50C62HX/XEE. 50 inch plasma. Sound but no picture.

With dead fuse, I meant it was "open". I tested them with the beeper on a multimeter and the "dead" ones didnt beep, making me believe that they were blown.

I will test the transistors as you say and report back here.

What can be done if the upper buffer board is shorted? I assume just buy a new one?

unless you have the ability to replace the Ics which is not a beginner job yes but finding a buffer and cheap will be near impossible. probably some repaired ones available but for the age of the TV you'd have to way it up. repairing the ymainn sometimes can be as straight forward as replacing 88n30 fets which have shorted but sometimes ther's more

[tw2005]

Re: Samsung PS-50C62HX/XEE. 50 inch plasma. Sound but no picture.

Oh, and that video is Tom66

This one https://www.youtube.com/watch?v=25HTy6esBHs is the same Tv setup as yours

[Eskil]

Re: Samsung PS-50C62HX/XEE. 50 inch plasma. Sound but no picture.

Cool. I should have known a guy like that would be hanging out in this place.

I have now gotten the 88n3Ws and the other transistors out. I know that they are different kinds of FETS, but Im not sure if they have to be tested in different ways or not. Im not even sure what kind of voltage they activate at. It would be silly to be poking them with my multimeter if they only work at 300 volts or something. The datasheets are a bit confusing, especially since English isnt even my first language.

[drussell]

Re: Samsung PS-50C62HX/XEE. 50 inch plasma. Sound but no picture.

Usually if they aren't shorted they are still fine.

Not a definitive test but ones shorted between any two pins are definitely bad.

[Eskil]

Re: Samsung PS-50C62HX/XEE. 50 inch plasma. Sound but no picture.

Ok, so I have tested all the 88N30W mosfets, the one K2837 on the heatsink next to the 88's and the one B20NK-50Z you mentioned. They all seem perfectly fine. All I did though was using this test since I only have a multimeter:

https://www.youtube.com/watch?v=RBJGOOTEwfU

What do I do now? :/

[Eskil]

Re: Samsung PS-50C62HX/XEE. 50 inch plasma. Sound but no picture.

Sorry for bumping, but I really dont know what else I can do. Like, how do I confirm for certain that one of the buffering boards have died for example, or are there other components I should test somehow?