Vizio E422VLE screen problems when cold started. Works fine after 20 minutes.

[SdlewisSr]

Hello everyone
I have a Vizio E422VLE that has start-up issues. When turned on after being off a few hours, it takes about 20 minutes for it to display the screen properly. This model has only two boards, power supply and main board (see photos). When I received this TV I found that the stereo audio out port had issues as well. It appears that a 3.5mm jack had been broken off in the port and an ink pen was used unsuccessfully to get it out. I removed the port (after taking the included photos) and the problem still exists. The port had three pieces of metal inside it. One thing that I did notice after removing the port is that the menu now worked correctly. Before removing it, the menu would not stay on the screen and the information displayed at the top right (input, channel #, etc) flickered and did not disappear as it should have. Now that the port is removed, the menu functions properly. The problem with the screen still exists. In short, during the first 20 or so minutes after cold start, only the top inch of the screen works properly. The rest has displays various screen states: vertical lines, black areas, faded area. I cannot adequately describe this behavior so I recorded a video that demonstrates from start-up to the time it actually functions as normal, about 20 minutes later. Please check out the video at (https://www.youtube.com/watch?v=0TpqaZntiq8). I would appreciate any suggestions you might have. I also checked the voltages from the power suppply to the main board and they are as they should be. I also checked what I believe are the voltage regulators (cannot locate a service manual).

CN202 voltages are:
Pin 1 (SB): +5.28v (+5.34v when turned off)
Pin 2 (SB): +5.28v (+5.34v when turned off)
Pin 3 (SB): +5.28v (+5.34v when turned off)
Pin 4 GND
Pin 5 GND
Pin 6 GND
Pin 7 GND
Pin 8: +12.27v
Pin 9: +12.27v
Pin 10: +12.27v
Pin 11 (Remote On/Off): +3.25v
Pin 12 (BL On/Off): +3.25v
Pin 13 (Lamp Status): +1.25mv
Pin 14 (Dimming Signal): +1.8v

UP13: (In) +3.3v (Out) +1.199v (Adj) +2.2mv
UP2: (In) +5.25v (Out) +3.3v (Adj) +2.04v

Video of problem.
(https://www.youtube.com/watch?v=0TpqaZntiq8)

[dick_barton]

Re: Vizio E422VLE screen problems when cold started. Works fine after 20 minutes.

Use a hair dryer to see if heating up any part of the circuit boards brings the picture up quicker.

[SdlewisSr]

Re: Vizio E422VLE screen problems when cold started. Works fine after 20 minutes.

Thanks dick_barton. I will give it a try and report back.

[SdlewisSr]

Re: Vizio E422VLE screen problems when cold started. Works fine after 20 minutes.

Unfortunately the hair dryer did not affect the behavior. I tried it on both the main board and the power supply/inverter board.

[dick_barton]

Re: Vizio E422VLE screen problems when cold started. Works fine after 20 minutes.

Try warming up the pcb strip hidden in the bezel which the two LVDS cables run to.

[SdlewisSr]

Re: Vizio E422VLE screen problems when cold started. Works fine after 20 minutes.

Thanks. Will give it a try.

[SdlewisSr]

Re: Vizio E422VLE screen problems when cold started. Works fine after 20 minutes.

Bingo!!!!
Great call dick_barton .
It took about one minute for it to start operating normally.
Now I just have to isolate it.
Thanks a bunch.

[dick_barton]

Re: Vizio E422VLE screen problems when cold started. Works fine after 20 minutes.

The long narrow pcb strip is attached via flat ribbon cables to the LCD Panel so extreme care is required not to break or damage the ribbons to the LCD Panel or at the panel.

If it is a faulty component on the pcb strip you may be able to isolate the fault using the hair dryer again.

[SdlewisSr]

Re: Vizio E422VLE screen problems when cold started. Works fine after 20 minutes.

Thanks again.
I really appreciate the help. This will be my first attempt at diagnosing a panel PCB strip/ribbon problem.
Will let you know what I find.
Have a blessed day/evening!

[vinceroger69]

Re: Vizio E422VLE screen problems when cold started. Works fine after 20 minutes.

maybe when you can get too them remove and clean both ribbon cable ends going to the panel pcb they maybe badly seated or dirty certainly worth a try.

[SdlewisSr]

Re: Vizio E422VLE screen problems when cold started. Works fine after 20 minutes.

If you are referring to the two cables going from the T-Con/main board, I don't think that's where the problem lies. I have one more test to do, but it appears to be isolated to the upper right corner, main board side of the TV. I have to let it cool down again to verify this.
Thanks

[vinceroger69]

Re: Vizio E422VLE screen problems when cold started. Works fine after 20 minutes.

hopefully its not a tab bond issue on that side.

[SdlewisSr]

Re: Vizio E422VLE screen problems when cold started. Works fine after 20 minutes.

I'm haven't taken a panel apart yet. So I am not sure exactly how the PCB and the panel are connected. I know that the tabs are bonded to the panel, I'm not sure how the PCB end of the tabs are connected to the PCB.

[vinceroger69]

Re: Vizio E422VLE screen problems when cold started. Works fine after 20 minutes.

bonded both ends on all the ones i have seen to date but until you can really narrow down the area its had to say as maybe a bad smd capacitor etc

[SdlewisSr]

Re: Vizio E422VLE screen problems when cold started. Works fine after 20 minutes.

Yeah, I hope its a component on the PCB.
Thanks again for the info.
Well let you know what I find.

[SdlewisSr]

Re: Vizio E422VLE screen problems when cold started. Works fine after 20 minutes.

I was checking out this video and the panel (2:44 into the video) and layout look very similar to mine. At 4:19 into the video the tabs and PCB are visible.

[SdlewisSr]

Re: Vizio E422VLE screen problems when cold started. Works fine after 20 minutes.

I forgot to put the link for the video.
Sorry.
https://www.youtube.com/watch?v=GcBwTums_mI

[SdlewisSr]

Re: Vizio E422VLE screen problems when cold started. Works fine after 20 minutes.

It's definitely the upper right corner. I focused the heat on the end two inches of the top side of the corner. It took all of 10 seconds. I could see the narrow strip at the top of the screen grow down line by line.
Later I will take the panel cover off and see what I can find.

[SdlewisSr]

Re: Vizio E422VLE screen problems when cold started. Works fine after 20 minutes.

The problem is one of the tabs. The end tab in the upper right corner (facing the rear of the panel) is the problem. I used a heat gun from a SMD rework station to heat the panel PCB only and it had no effect. Only when I used a hair dryer on the tab did the screen start to function correctly. When I removed the hair dryer and allowed a fan to cool the tab, the screen began malfunctioning as before. I created a video demonstrating this at (https://youtu.be/E_7tGQtU-fI).
Thanks dick_barton and vinceroger69 for your help. I really appreciate it.
Have a blessed day

[vinceroger69]

Re: Vizio E422VLE screen problems when cold started. Works fine after 20 minutes.

the hair dryer is heating the tab bond onto the lcd glass and also on too the pcb but is also heating up the pcb itself on that board theres some capacitors etc can you get a cardboard tube ie kitchen roll tube and aim the hot air down it and narrow down the area your heating up. Budm has done a thread on tab bond issues where he has added shims to the bonds maybe have a search on the forum and see if you can find his thread/guide.

Edit heres the link for his thread
https://www.badcaps.net/forum/showth...ab+bond+repair