Vizio SV470M IR sensor problem

[sansonet]

My TV was working fine, but lately I noticed that sometimes it doesn't respond to remote, which didn't bother me much because I mostly just need turn it on and off because I'm using it with player only. Lately it got worse, now I hardly can get remote to work with it at all. Tested batteries on remote, programmed universal remote - problem still exists. I had similar sensor board from 42" Vizio so I tried to replace - it still the same. Right now if I'll turn it on manually, and would press volume button on remote continuously, sometimes I'm getting response, but it stops and starts responding in random. It does the same with both sensor boards. Solder joints looks OK and tested OK with continuity tester. I'm adding pics of sensor boards - only difference between them is that board from another TV had ZDR1 component and original does not. They little different in size, but that board respond to remote sometimes too, so I think they pretty much the same. Anything else I should look at?
Added pic of main board too, part where sensor connects to it.

[sansonet]

Re: Vizio SV470M IR sensor problem

Looks like nobody in this forum experienced such problem or knows solution...
I have little more info, maybe this will help. In the last couple days was trying to locate problem and found few more things. I tried factory reset to see if it will help - it didn't, but turned out that not only IR sensor malfunctioning, but control buttons on TV too. After resetting it, I was using it to set TV to my preferences again. At first buttons was working, but then "menu", "ch up/ down" and "power" on TV stopped responding too. Volume and Input seems to be always working fine. Buttons are soldered directly to main board and there is no problem in soldering joints. I'll attach pic of main board - this one from internet, the same one like in my TV. I also did thing that Vizio site suggests - unplugging and holding power button, and resetting remote the same way too. Unplugging TV helps to restore functions, but only for short time - 5-15 minutes, seems less if remote or buttons are used. After that remote and power/ menu becoming unresponsive, but it might start working again in few minutes, then stops again.
Right now I plugged TV using wireless switch that I programmed to work with TV remote and I just keep it unpowered when not in use. I use it to shut TV down if I can't do it with remote.
I wonder if this is bad for TV to do it on regular basic?
Replacement main board is hard to find and ones that are available are way overpriced - over $100--200. I can find repair kit on ebay for this board, but not sure what in there and whatever it can fix problem. They also selling Eeproms for this board.
I could live with it like it is now because i use only one input for player, I don't change channels, volume can be controlled on player and I just need turn it on /off. But sometimes I need change settings - resolution, brightness, etc and don't want to loose this function completely.

[sansonet]

Re: Vizio SV470M IR sensor problem

I just realized that Vizio logo on front always stays orange, even with TV on and working. It was like that for while, but I missed it somehow - thought it should be this way. Now I think it might be connected to the problem. Hope somebody could respond with some ideas...

[sansonet]

Re: Vizio SV470M IR sensor problem

I really hope I will get some response here...
Any way, my TV stopped responding to remote completely, but I managed to get similar model with cracked screen not long ago. Cracked TV is 42" SV420M, but boards are compatible. I switched main boards and confirmed that main is culprit here. After reading some topics in here about voltage regulators in Vizio TVs, I measured all regulators on both main boards. All voltages are similar, but not on U4 (its marked L275 G9117) Also, bad board have U9, but I can't find it on good board.
This is link for good board http://www.shopjimmy.com/vizio-3642-...main-board.htm
Link for od faulty board http://www.shopjimmy.com/vizio-3642-...for-sv420m.htm

Here are readings:

Good Board

U2
PIN1 2.02V
PIN2 3.26V
PIN3 5.07V

U3
PIN1 2.02V
PIN2 3.23V
PIN3 5.03V

U4
PIN1 2.04V
PIN2 3.29V
PIN3 5.03V

U5
PIN1 1.99V
PIN2 3.23V
PIN3 5.03V

U6
PIN1 12.00V
PIN2 8.08V
PIN3 6.83V

U7
PIN1 2.04V
PIN2 3.29V
PIN3 5.02V

Bad board

U2
PIN1 2.01V
PIN2 3.28V
PIN3 5.07V

U3
PIN1 2.02V
PIN2 3.26V
PIN3 5.04V

U4
PIN1 0.0V
PIN2 1.24V
PIN3 3.26V

U5
PIN1 2.03V
PIN2 3.27V
PIN3 5.03V

U6
PIN1 12.00V
PIN2 8.00V
PIN3 6.75V

U7
PIN1 2.07V
PIN2 3.31V
PIN3 5.03V

U9
PIN1 0.54V
PIN2 1.78V
PIN3 3.26V

J6 IR connector

Good board:
Black wire 3.88V
brown wire 5.08V
red - 0V

Bad board:
Black wire 1.57V
brown wire 5.0V
red - 0V

I still would like to find out what is wrong with old board and possibly fix it. I might keep it as backup in this case.

[kasfamily]

Re: Vizio SV470M IR sensor problem

U4 possible different set on bad and good board. G9117 https://cdn.badcaps-static.com/pdfs/...79b822d535.pdf Check U8

[sansonet]

Re: Vizio SV470M IR sensor problem

OK, I see I missed U8 because it looks different -
PIN1 12.00V
PIN2 0.00V
PIN3 4.98V
It's marked AZ7805T-E1
looks like this one http://pdf1.alldatasheet.com/datashe...Z7805T-E1.html

Readings are from bad board

[kasfamily]

Re: Vizio SV470M IR sensor problem

Need a good photo U4 and U6

[sansonet]

Re: Vizio SV470M IR sensor problem

Here are pics of U4 and U6

[budm]

Re: Vizio SV470M IR sensor problem

"U6
PIN1 12.00V
PIN2 8.00V
PIN3 6.75V"
Are you sure you looking at the correct in/out/adj pins?
1 = adj
2= out
3 = in

U8 is fine, it is 5V regulator.

[sansonet]

Re: Vizio SV470M IR sensor problem

Sorry, I posted it in reversed order, correct readings:
PIN1 6.75V
PIN2 8.00V
PIN3 12.0V"

[budm]

Re: Vizio SV470M IR sensor problem

1117 adjustable, the output voltage should always be = to 1.25V ref + V adjust, so for this case the out put should be 1.25 + 6.75 = 8V, so it is OK.

[kasfamily]

Re: Vizio SV470M IR sensor problem

also U4
PIN1 0.0V
PIN2 1.24V
PIN3 3.26V Are you sure you looking at the correct in/out/adj pins?
1 = adj
2= out
3 = in

[sansonet]

Re: Vizio SV470M IR sensor problem

Probably reversed too, one on top is 3.26V and bottom is 0V

[budm]

Re: Vizio SV470M IR sensor problem

https://www.badcaps.net/forum/attach...2&d=1412866335
Are you sure that pin 1 (bottom pin as shown in the picture) is 0V, that pin 1 is the adjust pin which has two resistors connected to it, one resistor (R39) is connected between pin 1 and Ground, the second resistor (R37) is connected between pin 1 and pin 2.

[sansonet]

Re: Vizio SV470M IR sensor problem

Yes, that pin reads 0V, I tried few times because it got me suspicious, tried it again just now - the same result.

[Shane711]

Re: Vizio SV470M IR sensor problem

Long time with this post and no final answer as to the solution. Well I got one and I have the same problem. I been lazy these last few months but I got me a Sprinter Van now so I can get some of these fixed TVs out of my way and get some more fixed.

So I have this Vizio SV470M and the remote does not work and the volume does not work at all. I can still turn the TV on and off. Going to open it now and check the voltage regulators.

OK, so I do not think it is the regulators. I am going to suspect the EEPROM.

[sansonet]

Re: Vizio SV470M IR sensor problem

I am going to suspect the EEPROM.

I think it is EEPROM too, you can find them on ebay for ~$15 with free shipping.

[Shane711]

Re: Vizio SV470M IR sensor problem

I can program them myself. I already installed a new EEPROM but I need to test the TV more tomorrow. I was able to turn the volume up and down with the buttons but I need to connect a DVD player and test the remote. I will leave an update when the test is complete.

So have you fixed your TV yet? Do you need an EEPROM?

[sansonet]

Re: Vizio SV470M IR sensor problem

In post #4 I mentioned that I bought cracked screen SV420M which has compatible mainboard, I spent $30 on it so it was not bad, sold stand on ebay so I compensated most of it anyway, still have that cracked TV in my barn - cant decide if I should sell rest parts from it or keep as backup for mine (power board, etc). Thought about replacing EEPROM on old board and sell it too since they are pricey, but never got to it (yet )
My TV was working OK since mainboard swap and Im still using it.

[Shane711]

Re: Vizio SV470M IR sensor problem

Well I will let you know if the EEPROM fixed the TV by tomorrow night.