Vizio E320-A0 TV

[rlega]

Hello everyone,

I got a Vizio TV that has no power. When you connect the power cable, nothing happens. You press the power button on the remote, nothing, you press the power button on the side of the TV, nothing.

I checked the fuse (15A 250V) and there is continuity. I also checked thermistor (has a stamp of 2r55a) as well as the film capacitor (.33k275V), and I'm getting a reading. I also check for voltage going to the fuse and there is a voltage reading. I also checked the resistors based on their value and they are OK. I also checked the two capacitors 470mf 35v and their reading is correct, but when I check the middle capacitor (the long brown one), I do not get any reading with power or w/out power.

Anything else I'm missing that you guys can help me? Perhaps I might need someone to show me to test voltage after the fuse. I'm not too experienced when it comes to electronics.

Pictures attached
https://www.badcaps.net/forum/attach...1&d=1406095100

https://www.badcaps.net/forum/attach...1&d=1406095100



Thank you.

[stj]

Re: Vizio E320-A0 TV

rectifier BD100
check the middle pins for about 120v AC
and check the soldering on those pins - they look a little off in the foto.

if you get 120v AC then meter the outside pair for about 200-260v DC

[Agent24]

Re: Vizio E320-A0 TV

Please post photos of your own board, not ones from the internet. If there's a visible problem with yours you didn't see, we can't diagnose it from someone else's photos!

[rlega]

Re: Vizio E320-A0 TV

I'm going to try to explain in detailed, so I do not confuse you. Like I mentioned, I got the TV and it had no power at all. When power cable was connected, I did not see any light either.

When I took the back cover out, the first thing I thought would be damage was the fuse, but when I kept looking at the board I saw a black mark on a resistor (the picture i'm attaching has already been worked on, but I took a picture with the original resistor and marked where it was).

https://www.badcaps.net/forum/attach...1&d=1406262088

https://www.badcaps.net/forum/attach...1&d=1406262088

There were no readings to either of the two pinkish color resistors that I marked. There are other resistors on the board and those two were fine. They had readings and were correct based on their color code.

https://www.badcaps.net/forum/attach...1&d=1406262183

When I checked the fuse there was no continuity, so with the fuse blown, and two resistors not having any reading, I had three things so far that were damaged.

When I removed the board I noticed there was a black mark on the TV frame itself:
https://www.badcaps.net/forum/attach...1&d=1406262411

and looking at the otherside of the board, it was burned:
https://www.badcaps.net/forum/attach...1&d=1406262411


I could not find a pigtail fuse 15A 250V anywhere, but I found the following and it worked:
https://www.badcaps.net/forum/attach...1&d=1406262528

I did find the resistors based on their color code and changed the ones that were not giving me any readings.
https://www.badcaps.net/forum/attach...1&d=1406262664

https://www.badcaps.net/forum/attach...1&d=1406262901

Ok, I purchased a capacitance tester and arrived today. The long cap has a reading of 147uF. The thermistor had a reading of 2.5ohms (SCK 2R55A). The film capacitor had a reading, but I do not remember at the moment. If its needed I will check it again. The fuse has continuity. Checking voltage on the power connector itself, shows 120v coming in and passing through the fuse, but today when I check the rectifier like stj mentioned, it has no readings in the middle pins, and there is no readings with the outside pins.

I hope I explained clearly for you guys to understand

[budm]

Re: Vizio E320-A0 TV

OK, first of all the fuse is not 15A, that will be way too high for the TV, it is 3.15A fuse as printed on the board.So your board matched exactly as the shown in the pictures in your post #1, I need to be sure since I will have to trace the connection from the L and N of the AC inlet all the way to the two middle pins of the rectifier, there must be an open connection some where between the Bridge and the AC inlet.

[martino]

Re: Vizio E320-A0 TV

see pic..

[budm]

Re: Vizio E320-A0 TV

OK, take the resistance reading of the followings between:
For the LINE (HOT) 1 & 2, 2 & 3, 3 & 4, 4 & 5 they should all show <1 Ohms except 2~3 which is the Thermistor, it should be <5 Ohms.

For Neutral 6 & 7, 7 & 8 they should be < 1 Ohms.

[rlega]

Re: Vizio E320-A0 TV

Hello,

Thank you all for your help.

@budm - Jaja, I think I need glasses because I swear I saw 15A, but then I looked closely and saw 3.15A. I checked all the points for resistance like you told me to check and they all gave me the correct reading you mentioned.

@martino - I had power cord connected yesterday measuring different points and power was getting all the way to the fuse, but not out (I had the board connected with screws to the TV frame).
Today I tried to measure the 110V AC like martino mentioned, and as soon as I plugged the power cord to the board, a resistor blew up, so I could not test for 110V AC (power board was out, perhaps it needed to be screwed to the TV frame for to be grounded?)
https://www.badcaps.net/forum/attach...1&d=1406325290

https://www.badcaps.net/forum/attach...1&d=1406327852

I have two more resistors that I can replace, but I wonder why it sparked and blew up a resistor when it did not happen yesterday.

Thanks

[budm]

Re: Vizio E320-A0 TV

Post 4
"but today when I check the rectifier like stj mentioned, it has no readings in the middle pins"

Post 8:
"I checked all the points for resistance like you told me to check and they all gave me the correct reading you mentioned." Then post 4 statement cannot not be correct then.

Since the resistor sparked then the you must be getting AC to middle two pins of the rectifier then.

We need to trace out the connections of the resistor to find out how it is connected and what it is for.

[rlega]

Re: Vizio E320-A0 TV

I completely understand what you are saying about post 4, but I swear it did not have any readings yesterday. My dad was with me at that time and I told him to take the reading of the rectifier (he has more knowledge than me about electronics) and he did not get any reading either

I have changed the resistor again (the one that blew up). I'm going to check all the points you mentioned again, I'll be right back.

Question: does the board needs to be screwed to the TV frame to be grounded?

What other pictures you need?

Thanks

[budm]

Re: Vizio E320-A0 TV

You can work on the board by itself by laying on the card board or wooden table. I would power this board through the GFI outlet to protect yourself in case you touch the primary side of the circuit.
I have to study the bottom side of the board to see how that burnt out resistor is connected in the circuit, that will be very time consuming.
Right now we know that you DO have DC Voltage at the main filter cap.
FYI:
http://www.shopjimmy.com/vizio-0500-...upply-unit.htm

[Agent24]

Re: Vizio E320-A0 TV

I completely understand what you are saying about post 4, but I swear it did not have any readings yesterday.

Possibly an intermittent connection somewhere

[budm]

Re: Vizio E320-A0 TV

OK, I traced out the bottom side of the board, R150 (150K Ohms) is part of the snubber circuit to protect MOSFET Q150 which drives the main power transformer.
R157 (0.27 Ohms) is the Source resistor of the MOSFET Q150, so it means that more likely the MOSFET has shorted out between Source and Drain pin, also more likely the SMD SMPS IC 150 is also damaged.
For $35 you can get the replacement board from shojimmy.

[rlega]

Re: Vizio E320-A0 TV

@budm - The points you had mentioned on Post #7, I checked them back again, and they are all giving the correct numbers you mentioned.

@Agent24 - I just noticed one of the pictures that I had taken it shows the power cord connected and that was when I was testing the rectifier for voltage, that was lastnite, and it did not spark.
https://www.badcaps.net/forum/attach...1&d=1406331310

In other words, no worth buying parts to fix it?

Question: I found the MOSFET Q150, where is the SMD SMPS IC 150?

I think I'm better off buying a replacement instead of spending all this time on a power supply that its not that expensive, not only my time, but your time also.

Thank you much for the help. Really, really appreciate it!

[budm]

Re: Vizio E320-A0 TV

The 8-PIN SMD IC is on the bottom side of the board close to the MOSFET Q150.

[rlega]

Re: Vizio E320-A0 TV

Hello everyone,

I found a working power supply at a tv local store for $10

I got home and connected the power supply thinking I was going to see the Vizio up and running, and nope, it did not turn on

I still do not see any light, no backights working, it won't turn on using the power button on the side of the TV, and it will not turn on using the remote.

I took some pictures to see if anyone can tell me how to test power going to the main board and what is the correct reading for it. If any other picture/angle is needed, please let me know.

https://www.badcaps.net/forum/attach...1&d=1406593460

https://www.badcaps.net/forum/attach...1&d=1406593460

https://www.badcaps.net/forum/attach...1&d=1406593460

Thanks

[budm]

Re: Vizio E320-A0 TV

Check the DC Voltages on that white connectors to see what voltages you have and report the reading of each pin, use the chassis as the ground point for the mater black probe.

[rlega]

Re: Vizio E320-A0 TV

I checked voltage on white connector on main board
Pin #1 - 23.85vdc
Pin #2 - 23.85vdc
Pin #3 - no reading
Pin #4 - no reading

Thanks

[Agent24]

Re: Vizio E320-A0 TV

24v is a common voltage used in things so it is probably OK. You would have to find out what voltage is supposed to come out to know for sure, though. Pins 3\4 don't have a reading because they are ground (as shown by the silkscreen on the board)

[budm]

Re: Vizio E320-A0 TV

OK, at least now the power supply is working, now you need to find out why the main board is still dead.
Do you know the history of this TV? Was it hit surge, etc?