Sony XBR65x930D - left half screen is grainy

[misterhaus]

Hi, this is my first post - so thanks in advance for any assistance.

I have a Sony XBR 65x930D (manufactured in July-2016), which was initially showing a black screen, faint backlight glow, and played musical sounds when powered up. After some experimenting (mostly unplugging cable and re-plugging), including attempting hard-reset and firmware update, it is now showing video, but the left side of the screen is fuzzy/grainy. (See attached pic)

I am trying to decide if this could be the T-CON board, or the DPS board.
When I press on the upper right of the DPS board, or around the two video cables between DPS and TCON, it may go to a totally white screen, or more fuzziness appears on the screen. When warmer, it may change less when I press on boards/cables. Any tips on troubleshooting?

Here is the ShopJimmy link to the components for this TV: https://www.shopjimmy.com/sony/xbr-65x930d

I've attached pics of the overall back of the set as well as the DPS board which seems to be sensitive to causing the symptom.

Sony has a "No Power" extended warranty on this set - not sure if related: https://www.sony.com/electronics/sup...ticles/S1Q0526

Thanks for any assistance you may have!

Rich

[brucetv]

Re: Sony XBR65x930D - left half screen is grainy

Rich
This model does have a history of bad DPS boards and a batch of power supplies left the factory with free replacement. Our records show we replaced IC408 on the DPS board. In your case I would clean the ribbon cables with isopropyl alcohol and reseat the ribbon cable to see if that clears it up. If that don't help check VGL L voltages compared to VGL R voltage on T-con to see if they are the same. If not I would suspect a problem on that side of the T-con with the bad image.
Bruce TV

[misterhaus]

Re: Sony XBR65x930D - left half screen is grainy

Thanks Bruce for your reply!

VGL_L is -12.7 V
VGL_R is -3.4 V

Would this indicate a bad TCON board? That is what I understood from your comments above.

Sometimes I don’t get any display at all - just a black screen with backlight on, and I can send video input and hear audio fine.

[brucetv]

Re: Sony XBR65x930D - left half screen is grainy

Rich
That's quite a bit of difference so it's one of the things I would suspect. They are about $18.95 at www.tvpartstoday.com plus shipping. Any luck cleaning the ribbon cables?

[misterhaus]

Re: Sony XBR65x930D - left half screen is grainy

I removed all 4 of the ribbon cables (between TCON and display) and cleaned both ends.

At first I removed the two on the “bad” side of the screen. While removed I powered up the tv and had white screen on left half. The VGL_R was then the same as the Vgl_L (-12.7 V each).

To rule out the cables themselves, I swapped the pairs from left to right side. The problem is the same with all four cables installed. The left half of screen is still grainy/fuzzy. And, the VGL_R (actually left side of screen as viewed from front) is back at -3.x volts.

I’ve got a TCON ordered. Hopefully it will ship given the COVID situation.

I was curious to check some other voltages on the TCON - not really knowing what each is supposed to be.

Here are a few of them in case they are interesting.

VGL R -3.5
VGL L -12.71
VGL AA -7.42

VGH R -0.56
VGH L +29.9

VCL 2.99

VDAM L 8.8
VDAM R 5.64

[budwich]

Re: Sony XBR65x930D - left half screen is grainy

If the voltages were the same / equal when the cable was removed, it is likely that your problem is not the tcon, but more likely an issue with a component on the bottom edge board that connects to the panel. Try follow the voltages tracks from the place on the tcon to a point on the cable / connector and then across to the edge board. Then look at some of those component that may be associated with that voltage line.

[brucetv]

Re: Sony XBR65x930D - left half screen is grainy

+1

[misterhaus]

Re: Sony XBR65x930D - left half screen is grainy

Understood. I had pulled the edge trip off before to visually inspect the LCD ribbon cables connected to the edge boards, and didn't see anything visual. I may have a line on another TV just like this one - although if it's one of the edge boards next to the display, I don't think I can swap those (if they're attached to the LCD screen).

Are there any common failure components on those screen-connected boards?

[nomoresonys]

Re: Sony XBR65x930D - left half screen is grainy

Check the small MLCC capacitors on the "edge boards" check them for very low ohms in ohm mode of course, expect over 100 ohms on good ones.

[misterhaus]

Re: Sony XBR65x930D - left half screen is grainy

Thanks - that's what I'll do!

[budwich]

Re: Sony XBR65x930D - left half screen is grainy

Understood. I had pulled the edge trip off before to visually inspect the LCD ribbon cables connected to the edge boards, and didn't see anything visual. I may have a line on another TV just like this one - although if it's one of the edge boards next to the display, I don't think I can swap those (if they're attached to the LCD screen).

Are there any common failure components on those screen-connected boards?

you can't replaced the board... as suggested, if you are lucky and find a "bad cap" smd on the board, with careful soldering, they can be replaced.

[misterhaus]

Re: Sony XBR65x930D - left half screen is grainy

Well, a few updates, no success yet.

First, I had ordered a replacement TCON board before posting this thread, and as predicted, it didn't change anything. They key being that when the right-most of 4 LCD edge boards are disconnected (remove ribbon connecting two right-most edge boards), the TCON voltages are normal on both sides.

I've done a bunch of checking capacitors on the edge boards, found nothing less than kilohms - most are megohms. There are a couple of ICs on the edge boards. Googling didn't give a datasheet, although I could order them. I wonder if either of these ICs could be the problem? Pins are so small, hard to compare the left/right sides while powered up.
U3: "CMI CM632 6EBDNT01 1605-AAD"
U4: "i2142HS P550549"
(see image attached)

I'm having trouble thinking about how to trace the signals along the edge boards to decide what is altering the VGL and VGH voltages from what the TCON supplies. Is this best done while power off and ribbons removed?

Could it be the panel?

I powered up the set again, and collected a bunch of TCON voltages from the edge boards.

SIGNAL LEFT* RIGHT (ribbon connected / discon)
VDDAML 8.76 7.71 / 8.80
VCM_C 7.53 7.53 / 7.53
VCM_T 7.53 7.53 / 7.53
VGL_G -12.69 -1.48 / -12.75
VGL_AA -1.64 / -7.32
VGH 29.95 -0.75 / 30.67
VDD_A 17.62 11.58 / 17.67
V18DD. 1.76 1.77 / 1.79

* Left edge boards have similar voltage whether the two left boards are connected or not
** Right edge boards have ribbon between them, when ribbon connected, voltages go awry. When only the right edge board closest to TCON is connected voltages are more normal (3rd column above)

For fun (learning), I tried to document the gamma voltages. The PCB labels were hard to interpret the order... but the voltages looked like they stepped down somewhat evenly.

GAMMA (right edge boards):
3.01 3.76 7.54 9.53
0.46 5.49 6.05 10.98 11.48 12.30
7.66 9.53 12.29 12.29

[budwich]

Re: Sony XBR65x930D - left half screen is grainy

not sure I follow the "edge board descriptions", can you post a picture of the bottom of the panel / edge boards on the side of interest. Are you saying that there are a pair of edge boards on each "half of the panel"? If so, then there is a "U" ribbon that interconnects the "pair". Please confirm my "understanding".

[misterhaus]

Re: Sony XBR65x930D - left half screen is grainy

Yes, exactly. There are two edge boards for "left" and two for "right" half of screen.

The right two are connected with a ribbon cable between them. Same with the left.

Image attached.

[jjanssen7]

Re: Sony XBR65x930D - left half screen is grainy

"Right edge boards have ribbon between them, when ribbon connected, voltages go awry. When only the right edge board closest to TCON is connected voltages are more normal."

Sounds like your problem may be related to the far right bottom IC board which pulls the voltage down. (AKA what you call your "right edge board") What does the picture look like when all but that board is connected? (disconnect the ribbon connector going between to two right-side bottom IC boards?)

[misterhaus]

Re: Sony XBR65x930D - left half screen is grainy

@jjanssen7: In my table of voltages above, the third column is with the right most board disconnected. The voltages go to “normal” which supports the theory something is wrong on that board, or the panel section that connects to that board (I’m trying not to accept that possibility).
I’m not sure how to approach checking that board - should I check resistance between the VGH and VGL test points to ground on the same board?

[budwich]

Re: Sony XBR65x930D - left half screen is grainy

Yes, exactly. There are two edge boards for "left" and two for "right" half of screen.

The right two are connected with a ribbon cable between them. Same with the left.

Image attached.

OK... so... disconnect the "u" cable between the two edge boards (carefully... its unclampable like the tcon to panel cables). Then leave all the tcon to panel cables connected. turn the set on and look at the picture (post a new one). Any new observations?

[misterhaus]

Re: Sony XBR65x930D - left half screen is grainy

With the interconnect between the two right edge boards disconnected, I get the image attached.

The right side of screen is split in two patterns. Far right is evenly bright white.
Other half of right side is vertical strips of very light grey, with varying darkness from center to middle right.

[misterhaus]

Re: Sony XBR65x930D - left half screen is grainy

Some resistance measurements on the left and right outer most edge boards (while disconnected from interconnect to inner edge boards. My thought was to look for lower resistance on right board with “problem”.

Value Left / Right
VGH 787k / 400k
VGL_AA 4.1M / 3.9M
VGL_G 760k / 4.0M
VDD 23k / 23k
VDDA 2.3M / 2.5M
VDDAM 3.2M / 2.4M

Admittedly, a few of the Megohm values were changing (as caps charged?) so I approximated.

[budwich]

Re: Sony XBR65x930D - left half screen is grainy

With the interconnect between the two right edge boards disconnected, I get the image attached.

The right side of screen is split in two patterns. Far right is evenly bright white.
Other half of right side is vertical strips of very light grey, with varying darkness from center to middle right.

sorry but I don't think that is right or I am not seeing the whole screen. Plus, it looks like you don't have the tcon cables in place as requested. Please confirm.