Toshiba 58L9300U 4K 3D HDTV

[ljintexas]

At first I had a red LED in the lower right corner. Left it powered up for an hour or so..now when I turn on, I get green LED and some sound out of the speakers like static. I have green LED heartbeat on far right board that looks like main board. Flashing three times, over and over. I also have green LED on far left board with large heatsink..looks like a digital board. From time to time, LED is flickering like it is communicating. I checked labeled voltages on the smps and all seem to be present. I have not uncovered what I think is an LED driver board on upper left. My first foray into a 4K set. No display or backlight as of yet.

[ljintexas]

Re: Toshiba 58L9300U 4K 3D HDTV

No ideas as to where to look next? There is a 9 pin comm port labeled Service. I may try hooking a laptop up to it just for kicks.

[Hamie]

Re: Toshiba 58L9300U 4K 3D HDTV

Have you tried unplugging the tcon and turning on the tv?

[ljintexas]

Re: Toshiba 58L9300U 4K 3D HDTV

No sir, but I will. I think I have found an issue with the upscale board which fires the backlight. Looks like someone has tried to repair it..the leads(two yellow leads) from it to the LED Driver board had been pinched and were almost completely severed. I cut them clean and soldered them back together. Now I have continuity in both leads from connector to connector. Please see attached pics of someones attempted repairs. From back panel, looks like something hit this set, pinching the leads and possibly knocking these components loose.
Other than having a massive power supply and an upscale board with mucho more interior communication, this set is much like a normal lcd. I do have 24 volts from smps at all of the caps on the LED Driver board, just no fire up signal on the two yellow leads..

[ljintexas]

Re: Toshiba 58L9300U 4K 3D HDTV

Tried disconnecting output of tcon..no lights..reconnected..tried input..no lights. Upscale board should be here today.

[ljintexas]

Re: Toshiba 58L9300U 4K 3D HDTV

Well, the upscale board was the issue. As soon as the panel energized, I saw cracks that were not visible before. I examined the panel with a light and there were no visible cracks. This set had signs it was hit from the rear..I am now the owner of a full set of good boards for a 4K Toshiba. Yay me!