Vizio M65Q7-H1 Red Vertical Strips fixed by tape blocking LC1 signal to half of the panel

[howardc64]

Failure Symptom



No picture, just red vertical stripes. Google search shows quite common problem for these recent Vizio M series although red vertical stripe pattern may differ. Some call it "Netflix" boot screen haha.

Where is the short?

Panel has 4x buffer boards. Quickly found the 1/4 panel buffer board with the problem by selectively disconnecting buffer board flex cables.



Having recently fixed another Vizio with similar symptoms that was a shorted ESD diode array ( link ) Probed the ESD diode array but tested good. Also could not find any shorts on the buffer board anywhere. Finally used tape method and isolated to pin 6 which is the LC1 signal from the AUO S302-59 chip (can't find data sheet) Board labled this pin as LC1 signal. Tracing its path connects directly to COF/panel (red arrow point to where LC1 goes). Found this explanation ( link just read video descriptions ) on Vizio LC1 signal. Sounds like its vertical frame timing. Last pic shows perfect panel blocking out LC1 signal to the single buffer board.



Question

Probably can't do better than flex cable signal blocking repair since the fault is likely in the COF/panel. Please advise if better repair is possible. Thanks

[nomoresonys]

Another fine fix, thanks. Makes me wish I would have further investigated a vizio I gave away, that only had one fine red vertical line.

[nomoresonys]

Interesting that blocking that one path fixed both red lines.

[howardc64]

Interesting that blocking that one path fixed both red lines.

yes, the short caused no display other than the red vertical stripes. Getting rid of the short allowed the panel display circuit to function properly. LC1 is surely redundant on the other edge of the panel so now just relying on that one.

If you had single vertical line and if the rest of the picture shows, then its a different problem.

[nomoresonys]

Ah, I see, so mine was a different issue, had a normally functioning display with just a fine red line. I think it was a bad connection on a tab bond. Hell I'll never know for sure now that it's gone. My curiosity is still there, I just can't justify putting in the time, being a slow learner with horrible memory...it's a losing battle for me.

[howardc64]

After seeing this post ( link ) where TVS (Transient Voltage Supressor or also know as ESD Diode Array) tests good with diode test and no shorts but still caused a failure. Decided to relook at this TV again. Confirm the LC1 signal is connected to the TVS (D001, pin 2 red arrow in picture). Removed the TVS and the ribbin connector tape block for LC1 and TV works!

TVS is 4266H ( prior Vizio with TVS failure I fixed was 4264H link ) Replaced with littlefuse SP1064E (they sent me 5x requested sample, had 4 left over after last Vizio repair) and TV is good as new and properly fixed I guess I've got 3 more TVS to fix 3 more Vizios/HiSense

[lotas]

If the zener diode in the assembly has a leak and not a breakdown, then it cannot be checked with a multimeter.

[howardc64]

If the zener diode in the assembly has a leak and not a breakdown, then it cannot be checked with a multimeter.

Very good point. I guess if a blocked signal that revives the TV is connected to TVS, then TVS is suspect. Easy test is just removal. Hot air station is probably must for this 2.5mm x 1mm 10 solder point component.