Vizio VP503 HDTV10a Black Screen

[tom66]

Re: Vizio VP503 HDTV10a Black Screen

OK, on P7 -- check the attached pin outs for voltages. On P7 I expect a 5V or 15V standby voltage.

[MyHD120]

Re: Vizio VP503 HDTV10a Black Screen

Thanks. Was getting ready for the big winter storm from NYC to Boston. Might be losing power today or tomorrow. Will get these numbers to you ASAP.

[MyHD120]

Re: Vizio VP503 HDTV10a Black Screen

P7 pin outs on stand by. See photos

[tom66]

Re: Vizio VP503 HDTV10a Black Screen

OK, PSU is being TOLD to turn on, so check P6 in the same image for 15V supply.

[MyHD120]

Re: Vizio VP503 HDTV10a Black Screen

See Photos.

[tom66]

Re: Vizio VP503 HDTV10a Black Screen

OK, so as expected the Panasonic PSU is working, the Vizio parts are probably failed. We need to look at that DC-DC converter board. Also, have you checked the voltage regulators on the main board? Very common issue with Vizio main boards.

[MyHD120]

Re: Vizio VP503 HDTV10a Black Screen

. We need to look at that DC-DC converter board.

How would I do this?

Also, have you checked the voltage regulators on the main board? Very common issue with Vizio main boards.

So, I'll have to pull the Main and remove the voltage regulators to check them? I think I have something about checking them.

Going back a bit: I mentioned that after power on I get shut down after 30 seconds. LED goes back to orange.

Also, the LED's on the SC and SS boards fade out 20 seconds after power on.

Do these symptoms tell you anything?

[MyHD120]

Re: Vizio VP503 HDTV10a Black Screen

I'm now reading retiredcaps, "How to test a voltage regulator". Good stuff.

[tom66]

Re: Vizio VP503 HDTV10a Black Screen

It tells me that Vsus is coming up but then shutting down after some time probably due to main board problem.

[bjorkson]

Vizio VX32L black lines

I have a 32in Vizio LCD VX32L with constant black lines on the screen. Do you guys think this is a bad inverter or t-con board? Or bad LCD panel?
I have attached a pic...any help is appreciated. Thanks.

[tom66]

Re: Vizio VX32L black lines

I have a 32in Vizio LCD VX32L with constant black lines on the screen. Do you guys think this is a bad inverter or t-con board? Or bad LCD panel?
I have attached a pic...any help is appreciated. Thanks.

You really need to put that in a separate thread. We will keep discussing the VP503 here. If you need help, PM a moderator. I am not a moderator.

[MyHD120]

Re: Vizio VP503 HDTV10a Black Screen

Regulator Tests: I hope I get this right.

(U15) 1084 center leg not connected

Pin 1; 2.078v
Pin 2; 3.321v
Pin 3; 5.17v


(U19) 1084 center leg not connected

Pin 1; 12.52v
Pin 2; 2.478v
Pin 3; 5.18v

(U20) 1084 center leg not connected

Pin 1; .555v
Pin 2; 1.803v
Pin 3; 3.294v


(U16) 7805CT (ON MC)

Pin1; 12.01v
Pin2; 0v
Pin 3; 5.04v


(U22) AMC 1117 (F0816G)

Pin 1; 2.09v
Pin 2; 3.339v
Pin 3; 4.93v

(U21) AMC 1117 (F0816G)

Pin 1; 0v
Pin 2; 1.25v
Pin 3; 2.486v


(U27) AMC 1117 (F0816G)

Pin 1; 2.074v
Pin 2; 3.325v
Pin 3; 5.18v

[martyparish]

Re: Vizio VP503 HDTV10a Black Screen

I'n no expert but U16 looks suspect. You may want to double check that one just to be sure of the readings.

[MyHD120]

Re: Vizio VP503 HDTV10a Black Screen

Rechecked U16. All voltages are the same as above. Pin 2 sometimes shows a .2Mv.

U27 above should be labeled U17

[retiredcaps]

Re: Vizio VP503 HDTV10a Black Screen

U16 is correct. It is your classic 7805 5V regulator.

On U19 for pin 1, do you mean 1.252 and not 12.52V?

[MyHD120]

Re: Vizio VP503 HDTV10a Black Screen

U16 is correct. It is your classic 7805 5V regulator.

On U19 for pin 1, do you mean 1.252 and not 12.52V?

My bad. 1.252. If you see any bad regulators can you point me directly to where I can buy the part and the exact part number? I cannot understand those datasheets.

[MyHD120]

Re: Vizio VP503 HDTV10a Black Screen

Bump

[tom66]

Re: Vizio VP503 HDTV10a Black Screen

The regulators look OK. When you press the power button does anything on P6 change?

[MyHD120]

Re: Vizio VP503 HDTV10a Black Screen

During standby, all are in the mv stage. Power on changes pin 7 & 8 (?) to 15.26v. See photo from post 45 above.

[tom66]

Re: Vizio VP503 HDTV10a Black Screen

OK, so since the PSU is working fine, the problem is on the main board -- a very common defect with Vizio TVs. If the regulators are fine it could be a firmware issue, but you may need to simply swap the board out.