VIZIO SV470M orange to white logo

[CraigR]

VIZIO SV470M push power and logo goes from orange to white and no picture or backlight flash. 2 plugs on the power board. First plug DIM=2.71V INV_ON=0V Status=0V ACDET=0V second plug ON_OFF=3.1V next 3are marked 12V=12.17V next 5 are GND and last 3 are marked ST/+5V=5.16
Checked all electrolytic caps with ESR70 and all good. Also looked at solder joints under lighted magnification and good. No signs of anything getting hot either.

[Ltank]

Re: VIZIO SV470M orange to white logo

I had a Vizio that did the same but was a different model. Check all the LDO voltage regulators on the main board. The voltage was just a little low but enough to prevent the set from turning on.
I could not read the parts or silkscreen from the picture. Could you post a clear picture?

[Ltank]

Re: VIZIO SV470M orange to white logo

l looked at ShopJimmy and they are out of main boards (3642-0692-0150) for you set. But i did get a clearer pic of the silkscreen for the voltage regulators.
You tube (norcal15)has good videos but he doed get to checking the voltage regulators.

https://www.youtube.com/watch?v=cNFzBJELFoU

Check U2, U3, U4, U5, U6, U7, U8 and U9. They shoul be within 10%
The one leg will be the voltage in, another will be voltage out and one will be at gnd or close to it. I could not see what the actual part numbers are on my smart phone.

[CraigR]

Re: VIZIO SV470M orange to white logo

I just measured what I could see. it goes from left to right.
U9
556mV
1.8V
3.29V

U5
2.04V
3.2V
5.07V

U3
2.04V
3.29V
5.03V

U7
2.03V
3.28V
5.07V

U6
6.96V
8.21V
12.13V

U2
2.05V
3.29V
5.10V

U4
1.46mV
1.25V
3.29V

[CraigR]

Re: VIZIO SV470M orange to white logo

Yep, seen all his videos and Tampatech's also.

[budm]

Re: VIZIO SV470M orange to white logo

They are within spec.

[Ltank]

Re: VIZIO SV470M orange to white logo

Your first entry states " INV_ON=0V Status=0V ACDET=0V ". Unplug the set. Can you disconnect all cables to PS except AC in. Then use a 100 to 500 ohm resistor to jumper the INV_ON to the 5vdc standby voltage. Will the PS turn on? If so turn it off, unplug set then connect the inverter cable and retest. Do you get 24vdc? Did backlights turn on?

[CraigR]

Re: VIZIO SV470M orange to white logo

Ok, INV_ON jumped to 5V all cables off except power cord. I did not hear any click or anything when plugging the power cord in. I connected the back lights and tried again and nothing. 133 ohm resistor.

[budm]

Re: VIZIO SV470M orange to white logo

To force on the Backlights, you also need to force on the PS_ON pin (to turn on the PFC and the main power supply) beside the Inv_on PIN, some time you will also need to feed the DIM pin.

[CraigR]

Re: VIZIO SV470M orange to white logo

Ok then, what should I try next?

[budm]

Re: VIZIO SV470M orange to white logo

So you also jump the PS_ON pin with 1K resistor to the 5VSTBY too?

[CraigR]

Re: VIZIO SV470M orange to white logo

That made a difference. The board came on and then the backlights also.

[Ltank]

Re: VIZIO SV470M orange to white logo

Seems to me if you can make the PS switch on and the backlights power up, then its most likely the main board. Do you get any sound with source to any of the HDMI inputs?
Any OSD?

[CraigR]

Re: VIZIO SV470M orange to white logo

I have nothing to test HDMI but put a DVD player on RCA cables and cycled through the inputs by pushing the input button and waiting 3 seconds before pushing it again.
I get no sound and even with a big maglight I don't see anything on screen like menu.
I did see there is an EEPROM replacement for this main board. But systems don't quite match.

[CraigR]

Re: VIZIO SV470M orange to white logo

So what do you think? try EEPROM or just get a mainboard?

[Ltank]

Re: VIZIO SV470M orange to white logo

EEPROMS cost 25 or so bucks and may not fix it. I would get another main board

[CraigR]

Re: VIZIO SV470M orange to white logo

only 1 mainboard on ebay and $100 don't think so.

[Ltank]

Re: VIZIO SV470M orange to white logo

ShopJimmy has eeproms for 30 bucks plus shipping. That about half the price of a used board. No guarantee that the eeproms will fix it. EBay may have one for less.

[CraigR]

Re: VIZIO SV470M orange to white logo

eeprom did not fix it and I can't find a used board anyplace.

[CraigR]

Re: VIZIO SV470M orange to white logo

Ok, this is weird. I stopped messing with the TV last night to go to bed but forgot to unplug it. Now I just went in the shop and here the TV was on and working?? I shut it off and unplugged it for an hour then plugged back in and turned on and works fine?? WTF?? Anybody have any ideas on this or what I should look at now to keep it working?