Vizio VA320m Black Screen Help!

[Adam925]

My Vizio VA320m recently just stopped producing an image. I use this TV currently as a Monitor for my PC. i was in the middle of browsing the internet when all of a sudden a noise came out of the speakers and a little Black Blank Box appeared in the top right corner of the TV and then everything went black.
The Vizio logo still turns from Orange to White when turning the power on but no Picture or sound. I have tried all the HDMI ports but still no picture or sound. Any ideas or help on what to do next would be much appreciated.

[budm]

Re: Vizio VA320m Black Screen Help!

Please upload good clear pictures of the whole backside of the TV showing all the boards so we can see what we are dealing with.

[Adam925]

Re: Vizio VA320m Black Screen Help!

Here are the images you asked for.

[budm]

Re: Vizio VA320m Black Screen Help!

https://www.badcaps.net/forum/attach...8&d=1502911116
There are two white connectors on that power supply board; one goes to the main board, another one goes to the inverter board, we need to the DCV reading of those pins on the connector after the TV is turned on by the power switch.
There are pin names printed on the board so make sure to report the readings with pin name and follow by the Voltage reading so we can see if Voltages and the command signals are all there or not.

[Adam925]

Re: Vizio VA320m Black Screen Help!

Here are the readings you requested
Connector CN902 to Main Board
1- 00.1
DIM- 03.6
12v- 12.0
12v- 12.0
GND- 00.0
GND- 00.0
GND- 00.0
24v- 24.5
24v- 24.5
PS - 04.9
5v - 05.0
12 - 05.0

Connector CN903 to Inverter Board
24v - 24.5
24v - 24.5
24v - 24.5
24v - 24.5
24v - 24.5
GND - 00.0
GND - 00.0
GND - 00.0
GND - 00.0
GND - 00.0
DET - no wire present
ON/OFF - 00.1
DIM - 03.6

[budm]

Re: Vizio VA320m Black Screen Help!

OK, you have all the correct signals and Voltages except the ON/OFF (BL-ON) to turn on the backlights circuit, it should be >2.5Vdc for the backlights circuit to turn on, it comes from the main board.
You have 1 -00.1. No name for that pin? It looks to be the same as ON/OFF pin.
12 - 05.0: Is this pin labeled as 5V?

[Andrew F. Ali]

Re: Vizio VA320m Black Screen Help!

Pin1 on CN902 and ON/OFF Pinon CN903 should be 5.0Vdc or there about. No ON/OFF signal coming from the Main Bd.

[Adam925]

Re: Vizio VA320m Black Screen Help!

Here is a closeup view of the 2 connectors. I wrote for the pins exactly what you will see in the images.

[Adam925]

Re: Vizio VA320m Black Screen Help!

by the looks of it on CN902 pin 1 is ON/OFF

[Adam925]

Re: Vizio VA320m Black Screen Help!

I did another reading on pin 1 and on/off from CN902 and CN903
and both of those were 0.09

[Adam925]

Re: Vizio VA320m Black Screen Help!

Pin1 on CN902 and ON/OFF Pinon CN903 should be 5.0Vdc or there about. No ON/OFF signal coming from the Main Bd.

so what does that mean exactly?

[maxvalutech]

Re: Vizio VA320m Black Screen Help!

The main board sends voltage change signals to turn on power supply and this looks OK then it sends signal to turn on backlight via inverter and that doesn't seem to be happening. Strange you have no sound as voltage looks to be there OK. For this set I don't know if signal voltage goes high or low Andrew probably does.

[maxvalutech]

Re: Vizio VA320m Black Screen Help!

Just adding to the above if you test voltage for backlight on/off in standby then turn on and having left probes in place you see what changes. If nothing either fault on main or if a flicker on dmm possible problem with inverter.

[budm]

Re: Vizio VA320m Black Screen Help!

Here is a closeup view of the 2 connectors. I wrote for the pins exactly what you will see in the images.

OK, so PIN 1 is ON/OFF, and pin 12 is 5V.
You can force on the backlights by disconnecting the ON/OFF wire going back to the main board FIRST, then use 470~1K ressistor (1/4 W will be fine) hook up between ON/OFF pin and the 5V pin to see if the backlights will come on; you should see the image on the screen and all the functions should work if the only fault is ON/OFF signal, if not then you have more than just bad ON/OFF signal.

[Adam925]

Re: Vizio VA320m Black Screen Help!

OK, so PIN 1 is ON/OFF, and pin 12 is 5V.
You can force on the backlights by disconnecting the ON/OFF wire going back to the main board FIRST, then use 470~1K ressistor (1/4 W will be fine) hook up between ON/OFF pin and the 5V pin to see if the backlights will come on; you should see the image on the screen and all the functions should work if the only fault is ON/OFF signal, if not then you have more than just bad ON/OFF signal.

i really have no clue what that means. 470~1K ressistor??

[budm]

Re: Vizio VA320m Black Screen Help!

i really have no clue what that means. 470~1K resistor??

Well, please tell us then how much experience you have as far as fixing electronics down to component level. Do you have tools to do any soldering works?

[budm]

Re: Vizio VA320m Black Screen Help!

These are the boards for your TV, that model has more than one version so you have to match what you have on your TV.
http://www.shopjimmy.com/catalogsear...q=Vizio+VA320m

[Adam925]

Re: Vizio VA320m Black Screen Help!

Well, please tell us then how much experience you have as far as fixing electronics down to component level. Do you have tools to do any soldering works?

Yes, i have all the tools to solder if needed. I dont have resistors on hand i know that.

[Adam925]

Re: Vizio VA320m Black Screen Help!

Any chance of a step by step trouble shooting guide?

[Adam925]

Re: Vizio VA320m Black Screen Help!

OK, so PIN 1 is ON/OFF, and pin 12 is 5V.
You can force on the backlights by disconnecting the ON/OFF wire going back to the main board FIRST, then use 470~1K ressistor (1/4 W will be fine) hook up between ON/OFF pin and the 5V pin to see if the backlights will come on; you should see the image on the screen and all the functions should work if the only fault is ON/OFF signal, if not then you have more than just bad ON/OFF signal.

Ok so i de-soldered an old 470~1K resistor from an old creative Inspire T2900 i had collecting dust pulled a 'MacGyver' and "presto" we have Backlights.. No menu no splash screen or Vizio Logo... But Backlights we have. crossing my fingers that the rest is oh but a simple task.