RCA RWOSU7047 Distorted picture

[Nicktronic]

Hey, please the attached pics. This TV will turn on (Backlights on) but no picture provided. I tried disconnecting the right side LVDS cable between the tcon and buffer board (pic 1) and then the left side LVDS cable between the tcon and buffer board (pic 2). I get an image each time, but as you can see, there's a discoloration issue happening. But with both LVDS cables connected i get a black screen (BL ON though).

Just curious if anybody has seen this before? I will provide pictures of the boards shortly, I'm just in a rush and wanted to get this posted and see what the experts think!

Thanks

[Nicktronic]

Re: RCA RWOSU7047 Distorted picture

Sorry for the delay, I got the pictures uploaded.

I also took some measurements on the T-Con:

All GM V - 0
VGH - 0
VGL - 0
VDDA - 0

BUT! IF I DISCONNECT THE LEFT OR RIGHT RIBBON CABLE TO THE PANEL BOARD (or both at sametime), I GET THE FOLLOWING MEASUREMENTS:

Gamma V

14.99
14.23
12.27
10.97
10.19
9.77
8.21
7.15
5.58
5.17
4.40
3.11
1.15
0.39

VGH - 25.05
VGL - -6.06
VDDA - 15.93

I've changed the T-Con without success. Am I to assume its the panel??

[Biruslapio]

Re: RCA RWOSU7047 Distorted picture

I see some horizontal lines, probably panel failure since t-con replacement did nothing, inspect the panel boards for shorts and/or overheating components.

[Nicktronic]

Re: RCA RWOSU7047 Distorted picture

I see some horizontal lines, probably panel failure since t-con replacement did nothing, inspect the panel boards for shorts and/or overheating components.

I will, but why do all the T-Con voltages go to zero when both cables are connected? How could any components on the panel boards get hot if there is no signal from the T-Con?

[lotas]

Re: RCA RWOSU7047 Distorted picture

I will, but why do all the T-Con voltages go to zero when both cables are connected? How could any components on the panel boards get hot if there is no signal from the T-Con?

The protection is activated and the voltages in the T-CON DC / DC converter are turned off if there is a short or low resistance on these lines.

[Nicktronic]

Re: RCA RWOSU7047 Distorted picture

The protection is activated and the voltages in the T-CON DC / DC converter are turned off if there is a short or low resistance on these lines.

When I power on with only one ribbon cable connected (L or R), this IC goes to over 140F until the washed out/negative looking image appears (the ones that I shared in Post #1). Once the image comes up, it starts to cool down to around 86F. I can't find any information on the IC though.

Does anybody know what it does and if it's normal to get crazy hot?

[Diah]

Re: RCA RWOSU7047 Distorted picture

you have shorted gamma ic on T-CON

[Nicktronic]

Re: RCA RWOSU7047 Distorted picture

you have shorted gamma ic on T-CON

I already replaced the T-Con, no change.....

[Diah]

Re: RCA RWOSU7047 Distorted picture

I already replaced the T-Con, no change.....

you never wrote about replacing.... i am talking on yours first post the 2 photos you uploaded ob old or replacement t-con its shorted Gamma IC

[Nicktronic]

Re: RCA RWOSU7047 Distorted picture

you never wrote about replacing.... i am talking on yours first post the 2 photos you uploaded ob old or replacement t-con its shorted Gamma IC

I did at the end of Post #2, but that's ok! Moving on, so what can I do if both T-Cons have the same result? The 2nd one is new from Shop Jimmy. Is the Gamma IC possibly dead on both? Maybe the panel caused it?

[Diah]

Re: RCA RWOSU7047 Distorted picture

sorry just i read at the end of post#2 ..
you replaced T-CON. but its far to call it new. the pictures show GAMMA fault. the IC you linked at post #6 are SPI NOR Flash Dual I/O . but its label look out as local manufactured by panel. so i dont know under which Taktfrequency this work, you may find from TV Spec picture Freq.

in general the SPI receive the Data direct from T-CON. so if the DATA Freq ( GAMMA ) fault it will effect it this why it become warm to hot and then cooling down after the image cleared.
you can check the VCC on pin 8 to know if its 3.3V or 1.8V. also you can carefully take it out and then turn on. if the image / half picture come clear or not.

[lotas]

Re: RCA RWOSU7047 Distorted picture

sorry just i read at the end of post#2 ..
you replaced T-CON. but its far to call it new. the pictures show GAMMA fault. the IC you linked at post #6 are SPI NOR Flash Dual I/O . but its label look out as local manufactured by panel. so i dont know under which Taktfrequency this work, you may find from TV Spec picture Freq.

in general the SPI receive the Data direct from T-CON. so if the DATA Freq ( GAMMA ) fault it will effect it this why it become warm to hot and then cooling down after the image cleared.
you can check the VCC on pin 8 to know if its 3.3V or 1.8V. also you can carefully take it out and then turn on. if the image / half picture come clear or not.

What is this SPI NOR Flash Dual I / O, this is a VCOM signal converter.

[Nicktronic]

Re: RCA RWOSU7047 Distorted picture

What is this SPI NOR Flash Dual I / O, this is a VCOM signal converter.

I think I agree with @lotas, after reading a little bit about VCOM, it can cause the white picture that I'm seeing. Possibly the supply voltage is too low. Does anybody have a datasheet for this IC? I haven't been able to find one.

[Nicktronic]

Re: RCA RWOSU7047 Distorted picture

I took the following measurements of the VCOM signal converter;

left side ribbon cable connected, displaying like the picture in post #1, after the high temp run up as mentioned in post #6

pin 1 - 244mV
pin 2 - 244mV
pin 3 - 6.69V
pin 4 - gnd
pin 5 - 6.69V
pin 6 - 3.5V
pin 7 - 3.5V
pin 8 - 15.84V

right side ribbon cable connected, displaying like the picture in post #1, after the high temp run up as mentioned in post #6

pin 1 - 268mV
pin 2 - 268mV
pin 3 - 6.69V
pin 4 - gnd
pin 5 - 6.69V
pin 6 - 3.4V
pin 7 - 3.4V
pin 8 - 15.8V

Both ribbon cables connected

0V all pins

I can't find any information on this IC, see picture (same as post #6)

[Diah]

Re: RCA RWOSU7047 Distorted picture

What is this SPI NOR Flash Dual I / O, this is a VCOM signal converter.

the main talking are on Data Freq. i don't know what kind of LCD build in this set IPS / VA or TN !!

[Nicktronic]

Re: RCA RWOSU7047 Distorted picture

Most likely the panel causing my issue, but the TV got covered under warranty.

Thanks for the help