47LG5010 Tcon or panel Very hot ribbon

[london-freddie]

Hi everyone more help needed please
this one is a 47LG5010
when I got this tv it would power up to a dark blue screen only, no picture no sound.
My first thought on it was tcon or mainboard
changed mainboard no change still powering on to a very dark blue screen
moved on to tcon board and found that one of the ribbons from the panel to the tcon was very very hot, other ribbon cold
Disconnected hot ribbon and powered tv, it fired up to half a picture on screen.
Anyone any ideas on this have swapped ribbons left to right same both connected no power up disconnect right hand left hand powers up to a picture.
I must say the right hand ribbon gets very very hot very quick
I may be wrong I am no expert but to me this must now be tcon or the panel itself

[london-freddie]

Re: 47LG5010 Tcon or panel Very hot ribbon

tcon board with ribbon disconnected, half picture on screen, if I reconnect the ribbon no picture at all

[budwich]

Re: 47LG5010 Tcon or panel Very hot ribbon

my guess is that one of the panel drivers on that side of the panel is in trouble... :-(
check along the lower edge of the panel to ensure the edge boards (if any) are not touching the frame or other metal parts.

[london-freddie]

Re: 47LG5010 Tcon or panel Very hot ribbon

found this on panel driver board looks like C27 is the problem,

[vinceroger69]

Re: 47LG5010 Tcon or panel Very hot ribbon

possibly shorted out maybe worth measuring the same capacitor on the left side and replace it with the same.

[london-freddie]

Re: 47LG5010 Tcon or panel Very hot ribbon

measuring c27 in situ is measuring same as all the other caps on left and right boards

[budm]

Re: 47LG5010 Tcon or panel Very hot ribbon

There should be trace on the bottom side of the board that makes the connection to the top side of the board for that filter cap C27, same for the C15, 16, and 28.
Does the top terminal of C27 has electrical connection to the top terminal of C28?
The bottom terminals fo C15, 16, 27 , and 28 are all connected to the ground plane.
What is the resistance reading of that C27?

[london-freddie]

Re: 47LG5010 Tcon or panel Very hot ribbon

thanks for that yes top of c27 has connection with top of c28
bottom of c27, 28. 15 and 16 are all connected to ground

[vinceroger69]

Re: 47LG5010 Tcon or panel Very hot ribbon

as per budms qusetion post 7 What is the resistance reading of that C27?

[london-freddie]

Re: 47LG5010 Tcon or panel Very hot ribbon

what scale do you want me to measure c27 in

[budm]

Re: 47LG5010 Tcon or panel Very hot ribbon

200 Ohms SCALE, or AUTO. Just to be sure to report if the reading is in Ohms, K Ohms, or M Ohms.

[london-freddie]

Re: 47LG5010 Tcon or panel Very hot ribbon

0.03 on K Ohms all caps reading the same

[budm]

Re: 47LG5010 Tcon or panel Very hot ribbon

0.03 on K Ohms all caps reading the same

That is very low Ohms (30 Ohms).
Remove that C27 and take the resistance reading again between the two pads where C28 was installed.

[london-freddie]

Re: 47LG5010 Tcon or panel Very hot ribbon

will do please give me an hour or so need to pick kids up from school, will post asap

[london-freddie]

Re: 47LG5010 Tcon or panel Very hot ribbon

ok removed c27 trying to measure it now, however just powered tv up with c27 removed and both ribbons connected
picture on the previously bad side of screen is now perfect and flex is not now getting hot, however picture on other the other side previously ok is now all red vertical lines, doesn't make sense to me

[budm]

Re: 47LG5010 Tcon or panel Very hot ribbon

That is the filter cap so you should replace it and see, you will probably has to remove C28 to check the capacitance to see what the capacitance is, also check the DCV on the C28 before removing to see what DCV you have so you can will what the cap Voltage rating will be (the Voltage rating will have to be higher than the measured Voltage).

[freakaftr8]

Re: 47LG5010 Tcon or panel Very hot ribbon

The reason you also may be getting those lines because if you take a look at your first picture the ribbon cable has a burn mark going all the way through it you might have to replace that ribbon cable and then also check to make sure that the connectors on both the t-con board and the panel are not burned.

Try swapping ribbon cables from the good side to the bad side and see if the picture looks normal on the opposite side also

[budm]

Re: 47LG5010 Tcon or panel Very hot ribbon

The reason you also may be getting those lines because if you take a look at your first picture the ribbon cable has a burn mark going all the way through it you might have to replace that ribbon cable and then also check to make sure that the connectors on both the t-con board and the panel are not burned.

Try swapping ribbon cables from the good side to the bad side and see if the picture looks normal on the opposite side also

Good eyes!

[CapLeaker]

Re: 47LG5010 Tcon or panel Very hot ribbon

Good eyes!

better than mine!

[freakaftr8]

Re: 47LG5010 Tcon or panel Very hot ribbon

Lol I had to look twice and saw it.