DSE GE6839. Backlight OK no picture no menus etc sound ok

[maxvalutech]

Friend asked me to look at this Chinese generic a cheapie marketed by local chain which went into liquidation. Set has been wall mounted outside but kept covered when not in use and prob about 4yrs old. Turns on OK in normal course and has sound just no picture and no menu or other display. There is 12v both sides tcon fuse. No obvious signs of anything wrong on combined power and main. Tcon main suspect but its lead to screen is bonded at tcon !!! That must have saved them 15c . Not really worthwhile spending much time or money on this 27.5" set as newbies only about $150/180. Just posting in case someone has experience with these.

[R_J]

Re: DSE GE6839. Backlight OK no picture no menus etc sound ok

If you had a scope you could check if the video signals were on the lvds cable or not, no video on the lvds cable would indicate a main board fault, if the signals were there it could be tcon or panel.

[dskall]

Re: DSE GE6839. Backlight OK no picture no menus etc sound ok

Have you checked for common voltages on t-con?
Funny I saw a t-con on ebay for one like this. I messaged the guy and asked him if he knew how to attach it to the panel. He pulled the listing

[R_J]

Re: DSE GE6839. Backlight OK no picture no menus etc sound ok

I found this info for the panel, but I don't think it will be much help.

[maxvalutech]

Re: DSE GE6839. Backlight OK no picture no menus etc sound ok

Thanks for the responses. There is minor voltages going via lvds to tcon being range up to one and a bit plus of course 12v. There are 6 regulators on main board and the two with mid leg free read 7.17, 15.25, 0.20 and 0.02, 11.95, 12.01 respectively and I don't know if that's good or bad!
The other 4 which are 1117 type seem to be OK reading 1.29, 2.53, 5.19 and 0.00, 3.30, 5.19 and 6.83, 8.09, 11.95 and 0.50, 1.83, 3.30
Appreciate any comments.

[dskall]

Re: DSE GE6839. Backlight OK no picture no menus etc sound ok

My limited experience is if you have a volt or little more on data lines they are doing something. They may possibly change a bit if you toggle menu.
T-con voltages (typical)
1. Vin (Vcc): 12Vdc or 5Vdc
2. Vlogic,LCM, Vddd,VCC): 3.3Vdc
3. Vda (Vs, Vsource,VDD, Vdda,Avdd): 14Vdc~20Vdc
4. Vgh (Vgon,VGHR, Von, Vddg): 20Vdc~30Vdc
5. Vgl (Vgoff,VST,VGHF,VGHEVEN, Voff,Veeg): -5Vdc~-7Vdc
6. HVDD about 8v
7. DVDD,VDDC 3.3v, 1.2v
8. VCOM about 5~10vdc (about half of Avdd)