Vizio Symptoms and Possible Solutions

[captainKKK]

Please post your SOLUTIONS and their related symptoms before you fixed it

[captainKKK]

Re: Vizio Symptoms and Possible Solutions

I have partially fixed my dead Vizio E371VL. After many hours of checking all the components and soldering, I have normal TV stations and sound, BUT an unusual remaining problem that I am hoping my fellow cappers can help solve.

My Vizio model E371VL will turn on every time and display TV channels, with audio, as normal, ONLY when there is a VGA or HDMI device plugged into the back of it and powered on. Once the TV is turned on a TV channel and working like normal with video and audio, it will continue to work until I turn it off. Once turned off, if the VGA or HDMI device plugged into the back is no longer powered up, the TV will power back on (white Vizio in bottom frame) with no back lights and no video display but only audio playing from the TV channel. What might be the remedy to fix this odd behavior?

[captainKKK]

Re: Vizio Symptoms and Possible Solutions

I am at the end of my rope. I want to say it is a bad MB U21 but I am not sure. My main board is a 3637-0652-0150 Main Board. This thing has got me, all the voltages are correct on the 14 pins of the power board, when I get it turned on with a VGA attached to the back. So, something is keeping the power board's built in high voltage inverter transformers from getting the signal to ramp up and light the BL normally. Why does the attachment of an active VGA or HDMI device to the back send a signal from the main board to the PS to turn on the high voltage inverter transformers? I have the 0500-0407-1020 Power Supply / Backlight Inverter. If nothing is plugged into the VGA or HDMI at power up, the PS's main cap reads the correct 395vdc and all the of the 14 PS connectors are correct except the #13 Lamp voltage is not there until I power on with a VGA or HDMI active. Any ideas?

[capwizard]

Re: Vizio Symptoms and Possible Solutions

U18 EEPROM maybe corrupted or U46 Partial shorted. If I were you, I would change EEPROM first.

[budwich]

Re: Vizio Symptoms and Possible Solutions

you might check your grounds as some of those "plugs" provide "multiple groundings" with in the cable / connector.

As a test, get a "blank" vga connector (ie. no wire connections, ensure no pins are connected). Plug the plug into your tv and see what happens. Also possible that "hot plug" detection is having some impact.

[captainKKK]

Re: Vizio Symptoms and Possible Solutions

Thanks wiz and bud.

U46 not shorted. Seems there are several EEPROM available depending on the motherboard and which version, does it matter , or are they all ok?

available:
VIZIO MAIN BOARD 3637-0652-0150 E371VL E370VL E420VL E420VO EEPROM

I tried sending just 5 volts into VGA pin 9 when grounded to pin 10 and did not make a difference. Apparently it takes the VGA pp signals?

If I can get a vizio remote controller, I want to reset to factory and erase the cache to see if that helps...?

[captainKKK]

Re: Vizio Symptoms and Possible Solutions

Factory reset done, no improvement. New symptom, computer to VGA does not display but does display when attached thru HDMI. I need a beter microscope to look at that U46 area again. Prevous "owner" did some shotty soldering on that U18.

With no vga or HDMI plugged, pushing the power button changes the lower frame VIZIO to change from orange to white, and then results in no BL nor video, but the audio is playing. With bright light shining close to the screen, nothing is visible. There is no voltage at the "LAMP" wire connector on the PS. Then turn off and plug VGA from computer that is not even booted fully, results in completely NORMAL TV function, with 3.27 vdc at the "LAMP" wire connector on the PS.(meaning the BL is powered normally from the PS) Can even disconnect the VGA and the TV continues to work normally until I shut it off hours later. Your thoughts?

OK, I get it, I titled this thread WRONG, and I cannot edit it to state my model Vizio E317VL, so that I can get the experienced to take a look.........give me 40 lashes and I may try again.......

I know somebody in this place has had this issue and the fix is simple, but I started off ignorant.......

[captainKKK]

This is for a Vizio E317VL Symptoms and Possible Solutions

....

[budm]

Re: Vizio Symptoms and Possible Solutions

When you have PC that is powered up connected to VGA, pin 9 of the VGA of the computer will provide Voltage (steady 5V) to run the EDID EEPROM IC on the TV main board. HDMI Source also provide the steady 5V to run the EDID EEPROM IC on the main board.
https://cdn.badcaps-static.com/pdfs/...d7d44a6cf8.pdf
I would start checking Voltages around the HDMI IC and Voltages of the Voltage regulator IC's on the main board.

[ivtec]

Re: Vizio Symptoms and Possible Solutions

Captain ;Maybe you should reed these,who knows what you can find?




https://www.badcaps.net/forum/showthread.php?t=28199

[captainKKK]

Re: Vizio Symptoms and Possible Solutions

Thanks guys. My wife is now on me to toss it and stop fooling with this, but its my passion. Too bad I have no formal training, and I have to do it while my wife is not looking.... Nothing makes me happier than fixing electronics.
I was sure it was something on the mainboard, but not having a service manual, after more testing I found nothing suspicious.
So I starting thinking it is on the PS.......so help me out with this logic. I assume when I plug the 110vac in, the pinouts on the PS should only show the standby voltages of 5.3 vdc. Then pushing the power button, sends a signal from the MB to the PS to turn on the PS and the 12vdc circuits show up. And that is what happens. But, there is no voltage on the LAMP pinout of the PS. My question is (duh), does the PS PLACE the voltage signal at the LAMP pinout of the PS or does the that voltage come from the MB? Pls tell me how the LAMP voltage originates so that I can look for the fault in the right place......either in the PS or the MB.

There is another PS pinout#14 that is not enumerated. Does the MB send a signal to the PS to turn on the LAMP pinout, thereby initiating the high voltage transformers to power the BL? The more I think, the worse it gets.........

[budm]

Re: Vizio Symptoms and Possible Solutions

Main board sends out PS-ON, BL-ON, DIM control signals (steady state LO or steady state HI). Check Voltages on the main board as indicated.

[budwich]

Re: Vizio Symptoms and Possible Solutions

you need to do the test that I sugggested with a "blank vga plug". This will help narrow down things. Further, depending on what happens, then plug in a vga cable BUT don't have it plugged into the PC and observe what happens. These two tests will likely tell you if you are chasing a powering issues (as budm has suggested... because of vga coms desgin) or a grounding issue for similar reasons but different stimuli.

[captainKKK]

Re: Vizio Symptoms and Possible Solutions

The EDID EEPROM IC voltages are 3.25
will start checking individual Voltage regulator IC's on the main board
I will do the "blank vga plug" test next
Currently, noting the PS pinout voltages on 13 and 14, when the BL is initiated using VGA input (then unplugging VGA while running) with everything normal inc audio, the 13 pin shows 0.2 vdc, the pin 14 = 2.75 vdc.
Powering off the tv then back on w/o the VGA results in no BL (picture) with working audio from the channel previous on. Then, pin 13=0vdc and pin 14 = 0 vdc.
I assume the pin 14 is the dimming? The PS pinout legend is :
1-3=5vdc
4-7=SGND
8-10=12vdc
11=PSON
12=ON/OFF
13=Lamp
there is no designation for pin 14

Tracing pin 14 on the MB leads to U21. I need help identifying this IC. pictured. On that IC I read 4953GM and 13203E.......
google says 4953GM Clock Synthesizer / Jitter Cleaner | Mouser..........doesn't sound like that could solve my issue......?
thanks for all the help

[captainKKK]

Re: Vizio Symptoms and Possible Solutions

Consider this. Do I need to take this out of circuit to test? This is the only one of this type that has a short to ground. Sorry but I do not know what this is, pls tell me how to find or what to substitute. In the pics here this shows short to ground as indicated by the black arrows. The only designation on the top is A7 then a perpendicular 3.

[budm]

Re: Vizio Symptoms and Possible Solutions

Consider this. Do I need to take this out of circuit to test? This is the only one of this type that has a short to ground. Sorry but I do not know what this is, pls tell me how to find or what to substitute. In the pics here this shows short to ground as indicated by the black arrows. The only designation on the top is A7 then a perpendicular 3.

You to be clear as to which pin of the 3 pins is shorted to GND. What are the resistance readings for each pin with ref. to circuit GND?

[budm]

Re: Vizio Symptoms and Possible Solutions

Vizio 0500-0407-1020 Power Supply / Backlight Inverter
https://www.shopjimmy.com/vizio-0500...upply-unit.htm
https://assets.shopjimmy.com/media/c...1020-top_1.jpg
DPS-192AP A
11 PSON = PS-ON (input)
12 ON/OFF = BL-ON (input)
13 Lamp = Lamp Error (output)
14 Dim = Backlights dimming (input)

[captainKKK]

Re: Vizio Symptoms and Possible Solutions

Reading, learning, no solution yet... If this works fully after starting up with HDMI or VGA plugged, what would be more likely to NOT power on the DIM pin on the Power supply board? The PS or main board? Got any ideas to just "hot wire" the DIM pin to force the back lights when I push the power button?

[budm]

Re: Vizio Symptoms and Possible Solutions

You still did not show us what the Voltages readings are for the Voltage regulator IC's, Voltage around HDMI IC with and without HDMI source connected.
You can also try removing the Dim wire going back to the main board first then force the Dim pin on the power supply board high using 1K resistor between Dim pin and 5VSTBY pin.
Otherwise just buy working main board.

[captainKKK]

Re: Vizio Symptoms and Possible Solutions

Thanks BudM for the direction. Forgive my component miss naming.

Pls see the attached voltages as directed. Did I get it right? The ICs tested are circled in red. See the table of voltages and general layout to speed things along.

@budwich, thanks for the idea but it tells me nothing cause I cannot tell where this will lead. Pardon my lack of insight. When I plugged "blank" vga connector (ie. no wire connections, ensure no pins are connected). into the set it did not start the backlights and made no difference. Changed cables and nothing else. I could swear I saw the computer display on the TV when I first started with plugging the vga, but since the TV is face down and I put the mirror up awhile back I may have forgot things, or just dreamed them ......getting old is not for sissies....sorry....any more ideas?

@capwizard, thank you and I am still thinking on changing the EEPROM, but the guy that tossed this must have already done that because of his lousy soldering job.......so I am figuring that if it works well after I get the BLs on by using a plugged HDMI or VGA device, it is probably not the EEPROM......what do you think now?

TU8, U5, U8, and U4 are 1117 regulators, U31, U30 and U22 are designated as 402N

Updated