VA320M no picture no sound

[redmeat]

Hi my VA320M vizio tv is not working. The orange standby light is on then when I hit the power button it turns white. No picture or sound. Nothing seen with the flashlight test. CN902 voltage results below with power off and power on. Thanks for your help. Motivation high, skills lacking.

Powered off ----------------Powered on
O/F---0 V --------------------100 mV
Dim --0 V --------------------3.5 V
12V---82 mV-----------------12.5 V
12V---82 mV-----------------12.3 V
GRN ---0 V---------------------0 V
GRN ---0 V---------------------0 V
GRN ---0 V---------------------0V
24V ---60 mV----------------24.87 V
pson---60mV-----------------24.87 V
5V ----0 V ---------------------5 V
5V ----5.15 V-------------------5.12 V
12 ----5.12 V------------------5.12 V

[budm]

Re: VA320M no picture no sound

Hi my VA320M vizio tv is not working. The orange standby light is on then when I hit the power button it turns white. No picture or sound. Nothing seen with the flashlight test. CN902 voltage results below with power off and power on. Thanks for your help. Motivation high, skills lacking.

Powered off ----------------Powered on
O/F---0 V --------------------100 mV
Dim --0 V --------------------3.5 V
12V---82 mV-----------------12.5 V
12V---82 mV-----------------12.3 V
GRN ---0 V---------------------0 V
GRN ---0 V---------------------0 V
GRN ---0 V---------------------0V
24V ---60 mV----------------24.87 V
pson---60mV-----------------24.87 V
5V ----0 V ---------------------5 V
5V ----5.15 V-------------------5.12 V
12 ----5.12 V------------------5.12 V

Please recheck the Voltages, no way you can have 24.87VDC at PS-ON pin.

[redmeat]

Re: VA320M no picture no sound

Sorry about that!
Powered off ----------------Powered on
O/F---0 V --------------------100 mV
Dim --0 V --------------------3.5 V
12V---82 mV-----------------12.5 V
12V---82 mV-----------------12.3 V
GRN ---0 V---------------------0 V
GRN ---0 V---------------------0 V
GRN ---0 V---------------------0V
24V ---60 mV----------------24.87 V
24V----60mV-----------------24.87
pson---60mV--------------------5 V
5V ----0 V ---------------------5 V
5V ----5.15 V-------------------5.12 V

[budm]

Re: VA320M no picture no sound

Sorry about that!
Powered off ----------------Powered on
O/F---0 V --------------------100 mV
Dim --0 V --------------------3.5 V
12V---82 mV-----------------12.5 V
12V---82 mV-----------------12.3 V
GRN ---0 V---------------------0 V
GRN ---0 V---------------------0 V
GRN ---0 V---------------------0V
24V ---60 mV----------------24.87 V
24V----60mV-----------------24.87
pson---60mV--------------------5 V
5V ----0 V ---------------------5 V
5V ----5.15 V-------------------5.12 V

Main board is not sending the O/F (BL-ON) to turn on the backlights circuit.
What you can do is to remove the O/F wire going back to the main board first then use 470~1K resistor 1/4W between the O/F pin on the power supply board and the STBY 5V pin.
You will then turn on the TV and you should see the backlights come on and also the images on the screen if other main board functions are OK.

[redmeat]

Re: VA320M no picture no sound

Ok I will try to locate that and try it out. Is this just a diagnostic procedure or a work around fix? Thanks.

[budm]

Re: VA320M no picture no sound

That test is to find out if the backlights circuit backlights are OK or not, if the only problem we have is the missing BL-ON control then everything else should work and you should be able to see pictures and hear the sound, if not then you have more than just bad BL-ON problem.

[redmeat]

Re: VA320M no picture no sound

Ok I just got the resistor. Which pin is the STBY 5 v? There are 3 pins with 5 volts. Thanks.

[redmeat]

Re: VA320M no picture no sound

Ok I tried all the 5v pins and they all had the same results. When I push the power button the orange vizio sign turned white and the backlight came on but still no picture or menu.

[redmeat]

Re: VA320M no picture no sound

Does the above mean that the problem is the main board? The numbers on the board are715G3417-4. The sticker on the board says CBPFRD1KA1 IF it is the main board can it be diagnosed and fixed or time to say uncle?thanks

[budm]

Re: VA320M no picture no sound

Does the above mean that the problem is the main board? The numbers on the board are715G3417-4. The sticker on the board says CBPFRD1KA1 IF it is the main board can it be diagnosed and fixed or time to say uncle?thanks

Yes, you do have main board problem, you can try heating the board with hair dryer for a few minutes and then power up the TV to see what will happen.
There should be some Voltage regulator IC's on that board that you need to check the Voltages of all 3 pins.

[redmeat]

Re: VA320M no picture no sound

Heated it up and now it works!!. The only issue is it flickers when it first turns on. Do you think I still need to check the ic voltages? Thanks!

[budm]

Re: VA320M no picture no sound

That may be sign of bad caps or bad connection, so you may have to heat up the board in small section at a time to narrow down the location, at least it is a good progress.