Samsung UN48H5500AF - no standby, no video, no sound, backlights on when plugged in

[fixitjunkie]

Hello All,

Picked this up at a recycle center with hopes of a simple fix.
When plugged in, the backlights come on, two blue LEDs on the T-con board illuminate then one goes out. Cycling the on-off switch has no effect.

On the power supply board there are four test points labeled +, sine wave, sine wave and -. There is 120VAC across the sine waves and 113VDC across
+ and -. All the caps look good.

I'm not sure where to check for the standby voltage output?

Shop Jimmy's has plenty of PS boards, Main boards and T-con boards. All three would cost about $70, but if possible I'd like to narrow down any potential fix.

Any feedback is much appreciated. Thanks!!

[neilc6]

Re: Samsung UN48H5500AF - no standby, no video, no sound, backlights on when plugged

Sounds like a bad panel. Disconnect one side of the tcon at a time to see if one side displays half an image. If it does, you can try the tape cutoff method on the bad side. https://techhometravel.com/repair-of...lines-on-a-tv/

[fixitjunkie]

Re: Samsung UN48H5500AF - no standby, no video, no sound, backlights on when plugged

Thanks Neil. I found the test points for DC voltage signals. They all measured 12.6V. Tried the T-con disconnect method one side at a time and no change. Looks like this one is toast. Thanks again for the help.

[Davi.p]

Re: Samsung UN48H5500AF - no standby, no video, no sound, backlights on when plugged

The problem is much probably a small cap or diode on the panel distribution boards.. do this test get a 12v p. supply or make a flying link cable from psu to supply directly the tcon, detach tcon from mainboard, now touch repeatedly fast the tcon fuse with the wire, after some tens of seconds start to feel if some heat reach a component in dist. boards, but detach one board at time, usually there are two, found the warm one desolder it and test tv normally.

[fixitjunkie]

Re: Samsung UN48H5500AF - no standby, no video, no sound, backlights on when plugged

Thanks for the feedback Davi.p. This is going well beyond my capabilities. I'll put this one back in the grave and dig up something else.

[neilc6]

Re: Samsung UN48H5500AF - no standby, no video, no sound, backlights on when plugged

If no pic from either side, I would try replacing the tcon.

[dskall]

Re: Samsung UN48H5500AF - no standby, no video, no sound, backlights on when plugged

Sounds like bad t-con.

[handsworth]

Re: Samsung UN48H5500AF - no standby, no video, no sound, backlights on when plugged

I have had this problem on similar Samsung tvs. Turned out to be shorted panel board. Disconnect both tcon tabs and look for the blue lights on the tcon when tv is turned on. They should be lit and not go off. Try the tape method on the tabs and see if you get any kind of image. Thats a start.