VIZIO VO47L FHDTV10A No Video

[gethooked]

Hello all.

I have a Vizio VO47L FHDTV10A. While watching some MLB play-offs yesterday, the screen started to flicker and then went completely black. The Vizio logo still is amber in standby and white when the power-on command is given. There is sound, but the screen is completely black. The unit DOES power on and off.

I noticed a bulged capacitor on the power supply along with some burn marks.

I also tested the (F1) fuse on the Master Inverter and had 24V input and .9V output. I jumped the fuse and the TV powered on and I was able to see video, but the screen was flickering and a hissing sound was coming from the unit. The Slave has 24V on both sides of the fuse/

Transistor (O27) has 2.463V on the Input pin and 11.8V on the ADJ and Output Pins.

Voltage regulator (U3) appears to have 2.463V input and 1.025V on the output Pin. I believe it is supposed to be 12V?

I have posted some images in case someone is able to assist.

I thank you for your time and any help.

[budm]

Re: VIZIO VO47L FHDTV10A No Video

https://www.badcaps.net/forum/attach...0&d=1412786223
You have bad cap (bulging and leaking), you should recap the power supply board and re-solder that burnt section.

[gethooked]

Re: VIZIO VO47L FHDTV10A No Video

Thanks for the reply, budm.

Would it just be best to order a new Power supply, since its burned? Is that why I am not seeing the 12 volts on the (U3) regulator?

What about the bad fuse on the inverter? Should I just order a new inverter as well?

[budm]

Re: VIZIO VO47L FHDTV10A No Video

The 12V (for the main board)/24V (for the inverter board) will not be present until the TV is turned on, then the main board will send out the PS_ON signal to the power supply board to turn on the 12V and the 24V.
IC U3 is 7805 5V regulator which gets its input voltage from the 12V power supply.
Inverter board also has bad caps, the blown fuse can be due to shorted out power MOSFETs which went bad due to poor filtering because of those bad caps on the inverter board.
So you do need at least 2 boards.
The VZIO main boards are know for having bad voltage regulators. There should be at least two fuses on the main board, one is for the 5V, another one is for the 12V.

[gethooked]

Re: VIZIO VO47L FHDTV10A No Video

When I power on the unit, the input on the fuse on the master and the slave are receiving 24V. The output on the fuse on the master is only .9V.

Looks like I'll replace all 3. The P/S, master and slave boards.

[gethooked]

Re: VIZIO VO47L FHDTV10A No Video

Ok,

I jumped the fuse on the Master and mounted the inverters back on the set, and the TV is working great! I left it on for an hour and no overheating and perfect picture.

I do not now know how this is possible...... The U3 Regulator only has a 2.463V input and 1.025V on the output Pin.

I am still going to replace the boards due to the bad caps, but I was hoping someone could explain the U3 regulator issue.

Thanks again for your time.

[budm]

Re: VIZIO VO47L FHDTV10A No Video

Trace out the connection to the fuse on the main board for the 12V which should connect all the way back to the 12V output pin on the power supply board.

[gethooked]

Re: VIZIO VO47L FHDTV10A No Video

Will do budm. Thank you.

Also, do you think I can just get away with replacing the cap on the P/S based on these images of the underside of the board?.....Instead of replacing the board?

[budm]

Re: VIZIO VO47L FHDTV10A No Video

Yes, you can replace the caps on the board. The over heated section you can remove the old solder and then use flux and regular solder with lead to re-do the solder joints.

[gethooked]

Re: VIZIO VO47L FHDTV10A No Video

Which capacitors do you recommend?

Inverter Capacitors- These?

http://www.digikey.com/scripts/DkSea...84525692362255

Power Supply Capacitors- These?

http://www.digikey.com/product-detai...1576-ND/756092

[budm]

Re: VIZIO VO47L FHDTV10A No Video

The one on the second link is fine, but you should replace at least all the caps in the secondary side, there are at least two under the heat sink close to that bad one which are more likely to be bad due to heat.
Heat will destroy or shorten the life of the caps.

[gethooked]

Re: VIZIO VO47L FHDTV10A No Video

Thanks bud.

What about the inverter capacitors?

[budm]

Re: VIZIO VO47L FHDTV10A No Video

Since it has blown fuse on the inverter board, then you need ("When I power on the unit, the input on the fuse on the master and the slave are receiving 24V. The output on the fuse on the master is only .9V") to find out if the power MOSFETs are shorted out or not, and yes, you do need to change the caps on the inverter board also.
I use low ESR caps PANASONIC FM/FR/FC series from DIGIKEY.

[gethooked]

Re: VIZIO VO47L FHDTV10A No Video

Ok, I am ready to purchase these caps. Could someone please verify that these are the proper caps.

Inverter

http://www.digikey.com/product-detai...2417-ND/613778

Power Supply 470uf

http://www.digikey.com/product-detai...1576-ND/756092

Power Supply 1000uf

http://www.digikey.com/product-detai...2405-ND/613766

[gethooked]

Re: VIZIO VO47L FHDTV10A No Video

Bump.

I have these caps currently in my cart at digikey.

I just want to be sure I install the proper caps so that I do not create further damage. I'm not sure the height/length(dimensions) or resistance of the caps in the links above are correct.

Thanks again for any guidance.

[budm]

Re: VIZIO VO47L FHDTV10A No Video

You will have to measure the diameter and the height, especially the one sitting under the heatsink. Those caps series are fine.
Only two values of caps used on the board secondary side, it should have more than just 470uF and 1000uF.

[culmesm]

Re: VIZIO VO47L FHDTV10A No Video

Replace the cap so you will repair the power surce ,

[gethooked]

Re: VIZIO VO47L FHDTV10A No Video

budm,

I measured the caps and added all the caps on the secondary side to my cart at digikey.

Could you please take a look to see if I am purchasing the correct components.

I also added the U3 7805 regulator in case it is bad. I hope that's the correct replacement regulator.

[gethooked]

Re: VIZIO VO47L FHDTV10A No Video

Forgot the link

http://www.digikey.com/short/73mnzw

[budm]

Re: VIZIO VO47L FHDTV10A No Video

I do not know about the 10A fuse, which board is it for? How about the power MOSFETs on the inverter board? the fuse on the inverter board can be due to shorted out MOSFETs.
The caps are fine.