Vizio VO47LFHDTV30A Dead Set

[JMHammond]

This set has a 0500-0407-0680 (DPS-280LP) power supply. Through troubleshooting I found Q901 N-ch Power FET shorted which I replaced, along with R908 an SMD resistor open. The value of this resistor was blown off the top so I have no idea of the value. I have searched for a schematic for this supply to no avail. Does anyone have a schematic from which they could give me the value of this resistor(R908). Thanks much for any help. JMHammond

[ej207]

Re: Vizio VO47LFHDTV30A Dead Set

i would love this as well. same problem

[budm]

Re: Vizio VO47LFHDTV30A Dead Set

Q901 is for the STBY Power supply so it means that the SMD SMPS IC is more likely to be damaged also which you should replace otherwise you new MOSFET will be damaged. There may a fusible fuse that feed the B+ to this STBY section.
Can we see good clear pictures of you board both sides (the whole board, and also in 1/4 section so I can easily see the traces to trace out the connection)
The resistor that burn up may be for the Gated drive R/D network, also need to find out of there is <1 Ohm resistor connected to the Source pin that needs to be check to find out if it also went open circuit when the MOSFET shorted out.
This is the same board as yours?
http://www.shopjimmy.com/vizio-0500-...wer-supply.htm

[ej207]

Re: Vizio VO47LFHDTV30A Dead Set

First off apologize for thread highjacking, but we may have the same problem.

I tested all the pins to the bottom right of the board and no voltage?. Weird, and I made sure my multimeter was O.K. by testing other devices, even the wall outlet haha. Would this be a bad voltage regulator?

Quick history on the board, previous owner which is an old friend of mine replaced two resistors

• R901
• R601

I'm not sure when to the time it broke on me, probably a few months? But my girly and I was just watching the TV and it shut off, and i get no power led's nothing its completely dead. I have fixed some TV's in the past that just had the obvious blown caps. Here is some pics of the boards, which are exactly what you posted above.

[budm]

Re: Vizio VO47LFHDTV30A Dead Set

@ej, it will be better for you to start another thread so it will be confusing when two people are asking the questions.

[tinkerer973]

Re: Vizio VO47LFHDTV30A Dead Set

It would seem I have a similar problem with this PS board. I have voltage all across the board till I get to the secondary section, then I have nothing. I'm unsure of whether I just lost the 5v stby and the rest is fine, or if there are larger scale issues. I'm not sure where to begin from there. I have some electronics knowledge, I repair radio gear form time to time, but this is beyond what I'm used to working with. Hopefully someone can give me a hand getting this set fixed, Thanks

[budm]

Re: Vizio VO47LFHDTV30A Dead Set

@tinkerer: Same exact model power supply and TV model? It may be better to start a new thread with make and model.

[masessum]

Re: Vizio VO47LFHDTV30A Dead Set

In reference to the Delta power supply DPS280LP with the open R908 smd resistor in the standby 5V circuit, according to Fuji Electric's PDF on the Regulator controller IC FA5571, two example circuits show it as 22 Ohms. It worked for me!!

[trixter]

Re: Vizio VO47LFHDTV30A Dead Set

Currently working on this board. What are the ohms of R901/601? They are the same. From looking at the colors it is Red Red Silver Gold Silver. When I try to look this up I can't find a resistor with the third strip as Silver. I can see that one of the resistor is damaged. There is no reading across it.

[budm]

Re: Vizio VO47LFHDTV30A Dead Set

Currently working on this board. What are the ohms of R901/601? They are the same. From looking at the colors it is Red Red Silver Gold Silver. When I try to look this up I can't find a resistor with the third strip as Silver. I can see that one of the resistor is damaged. There is no reading across it.

0.22 Ohm MOX Flame proof type, if I am correct, it is also fusible resistor so if they are open circuit then you more likely have shorts circuit somewhere. I cannot clearly see them in the pictures.

[trixter]

Re: Vizio VO47LFHDTV30A Dead Set

Needed that info. I used a 22 ohm resistor. plugged it in and sparks flew and burnt up those resistors.

[slidewire]

Re: Vizio VO47LFHDTV30A Dead Set

In mine, the same board, R908 was also open, it had "60A" on top which crosses to 412 Ohms.

[DarinC]

Re: Vizio VO47LFHDTV30A Dead Set

I tried this with the standard component set from Shop Jimmy. I think I needed Q901 which the set didn't include.