55" Element tv turns on, no picture E4SJ5517BF

[Jerdejong]

Bought this tv for a fixer upper. The tv and backlights turn on but nothing is displayed on the screen. This model does not have a separate tcon board. It has a ribbon cable which goes from the main board to the buffer board attached to the bottom of the panel. Since the power supply tests good, it's gotta be the main board right? I tried three different main boards with no change. I do get voltage at some test points on the buffer board but I'm at a loss of what to do next. Any help would be appreciated.

[nomoresonys]

Re: 55" Element tv turns on, no picture

if you have 2 ribbon cables going to the panel driver board, try disconnecting one at a time then power up and check display, then do the other side, ALWAYS connect and disconnect cables with tv unplugged to avoid any errant power surges.

[dskall]

Re: 55" Element tv turns on, no picture

T-con will either be on main board or panel boards. Pictures and model # are always a nice touch if you really want help.

[Jerdejong]

Re: 55" Element tv turns on, no picture

Model E4SJ5517BF

[Jerdejong]

Re: 55" Element tv turns on, no picture

There's only 1 ribbon cable. Unplugging it does nothing.

[dskall]

Re: 55" Element tv turns on, no picture

Your t-con is on panel. Need some good pictures panel boards.

[Jerdejong]

Re: 55" Element tv turns on, no picture

Pics

[Jerdejong]

Re: 55" Element tv turns on, no picture

I'm assuming these panel boards are not replaceable since they look permanently attached

[dskall]

Re: 55" Element tv turns on, no picture

You are correct board swapping is not an option. Your only choice is board level troubleshooting and replacement of component. So checking voltages is first step. 12v input, hvadd, vcc, avdd etc. Your second most important picture is to blurry to read.

[Jerdejong]

Re: 55" Element tv turns on, no picture

Hope this one is better. My phone is old and doesn't take the best pics

[dskall]

Re: 55" Element tv turns on, no picture

You have vone, voff, vcc, avdd, hvdd voltage points you can check.

[Jerdejong]

Re: 55" Element tv turns on, no picture

Perfect I'll look into those, thanks. Off to bed for the night

[Jerdejong]

Re: 55" Element tv turns on, no picture

Here's some voltages on the panel board:
vone: .3v
voffe_11: .15v
vcc: 3.3v
(vcc_f_3.3v): 3.3v
(vcc_1.05): 3.4v
avdd: .03v
havdd: .02v
(vcc_3.3): .02v

[dskall]

Re: 55" Element tv turns on, no picture

What is part # on left chip? With power off and in continuity or diode mode read across the little brown capacitors around the 2 chips on the left.

[Jerdejong]

Re: 55" Element tv turns on, no picture

Is this the chip you're referring to? It's the far left chip

[Jerdejong]

Re: 55" Element tv turns on, no picture

The group of 4 circled capacitors(pic) measured .45v, but when switching the test leads, they measured 0v. The single circled capacitor(pic) measured 0v, with test leads both ways. The rest of the caps ranged from .1v - 1.8v. All were tested in diode mode.

[dskall]

Re: 55" Element tv turns on, no picture

Those 2 chips don't have the same numbers, do they? You are missing voltages from your dc to dc chip. Not sure which one it is. Not finding any info on the rt6939. I would think one would be gamma chip, but don't see any gamma points.

[Jerdejong]

Re: 55" Element tv turns on, no picture

I will check that 2nd chip when I get home from work today.

[dskall]

Re: 55" Element tv turns on, no picture

Closest I could find is this chip schematic, which looks similar to yours. I would look for HVIN12v around the chip. Check for shorts on points with no voltage. If you have voltage going to ic and no shorts I would replace RT6939

[Jerdejong]

Re: 55" Element tv turns on, no picture

Sweet thanks I'll check it out!