Vizio VW42L HDTV10A - Just replace caps? or test PS?

[LogicalTime]

I am playing around with (and trying to fix) a Vizio that sustained a fall and flickers just like the one in this video:
http://www.youtube.com/watch?v=GRNi7aHkNcw

The inverter caps look like they might be bad (see pics). The capacitors are labeled V9A PET, 35V, 470uF, 105C. I am not yet sure how to figure out what to replace them with, but I'll search the forum for info. I noticed there is a list of good capacitor brands on this site. I would like to know what some people with knowledge/experience think before proceeding.

Questions:
1) What do you think happened? Did the fall result in a power surge that blew the caps?
2) Do you think the powersupply could have gone bad, and result in blowing the caps again once I have them replaced? What do you think I should do?

Link to Pic Album

Thanks a bunch!

[awyatt2]

Re: Vizio VW42L HDTV10A - Just replace caps? or test PS?

had one and if i remember right it used phillips inverters, there is a mod for the inverters in this set. if it is the same as the one i had. the caps need to be replaced with low esr quality 105c temp. i used 125 c caps but i do not remember the value of them. google the board number if its phillips inverters and you willl find the mod. one for the master and one for the slave, seems like i used 470uf@50v but i am not sure. anyway i have used the tv for over a year on a xbox and no troubles. be sure you get a quality cap, not the cheaper standard like radio shack sells.i am tryinng to find a post that has the mod in it for you.

[tom66]

Re: Vizio VW42L HDTV10A - Just replace caps? or test PS?

Those bad caps can easily cause the flickering. Fall might be unrelated.
The mod is recommended, but only necessary if the inverter system does not work at all (i.e. no light whatsoever.)

[LogicalTime]

Re: Vizio VW42L HDTV10A - Just replace caps? or test PS?

Thanks!
The boards certainly are Philips and there are two boards, one labeled master and one labeled slave. I looked at the backs of the caps and found more details and updated the original post.

I will look around for how to determine a good replacement match. I am concerned about these being PET though, I guess some general capacitor replacement advice might not apply to PET types?

[tom66]

Re: Vizio VW42L HDTV10A - Just replace caps? or test PS?

No need to use PET capacitor -- that just indicates the plastic sleeve is made of polythene, I think.

[awyatt2]

Re: Vizio VW42L HDTV10A - Just replace caps? or test PS?

here is the mod, tom i dont think the fall did it, and i have a disc going you way in tomorrows mail. i did the mod on the boards myself but i have a hot air solder station and most of the attachments for what ever i run into. i still use a weller wcpt for the thru hole repairs. here is the mod.
Tom, i had planned on the disc going out in todays mail, made it yesterday but missed the mail today, slept late.

[awyatt2]

Re: Vizio VW42L HDTV10A - Just replace caps? or test PS?

just noticed you posted columbia, if its the same state you are around 96 miles from me.

[LogicalTime]

Re: Vizio VW42L HDTV10A - Just replace caps? or test PS?

I am going to try and replace the caps before attempting the mod. Replacing the caps will be a good warm up anyways.

So far I've learned I should find caps that:
have same uF (since it's usually easy)
have same or higher voltage
I can choose temp according to cap life if I like, I'll probably stick with (85-105C)
get some recommended quality name brand eg. panasonic?


here is the post I am looking at:
https://www.badcaps.net/forum/showpo...30&postcount=7

What do you think?

[LogicalTime]

Re: Vizio VW42L HDTV10A - Just replace caps? or test PS?

Ah, different Columbia. I updated my profile details

[tom66]

Re: Vizio VW42L HDTV10A - Just replace caps? or test PS?

Also, make sure dimensions will fit. Diameter and length are the critical measurements.
Panasonic FC, FM, FR are suitable, in order of "good" to "excellent".
Also a possibility: Rubycon YXF, ZL, ZLJ, same order.

[LogicalTime]

Re: Vizio VW42L HDTV10A - Just replace caps? or test PS?

Thanks tom, that helps me out a bunch :-)

[MisterD]

Re: Vizio VW42L HDTV10A - Just replace caps? or test PS?

Check all voltages on all regulators on the Main Board. and report here.

[LogicalTime]

Re: Vizio VW42L HDTV10A - Just replace caps? or test PS?

The caps are 18mm in length, 10mm in diameter. The slots they are resting in seem to be a bit bigger probably 20mm. Is mounting a capacitor lying down like this called something?

@MisterD which voltages? what do you mean main board? there are two boards with regulators on them master and slave. there is a powersupply. there are other boards too.

[LogicalTime]

Re: Vizio VW42L HDTV10A - Just replace caps? or test PS?

This is the cap I am looking at right now.
http://www.digikey.com/product-detai...441-ND/2433575

Should I go for a higher voltage (eg. 50 volts) or higher ripple current (eg. 2.20 A)?

[awyatt2]

Re: Vizio VW42L HDTV10A - Just replace caps? or test PS?

that is a general purpose cap, go for low esr. i use low esr in the entire set. let me see what i can find on digikey. you only have two types of caps, radial and axial. these are mounted horizintally instead of vertically. you also need to put these back pos to pos neg to neg. the stripe is neg side.

[awyatt2]

Re: Vizio VW42L HDTV10A - Just replace caps? or test PS?

try these
http://www.digikey.com/product-detai...7-1-ND/3134584

[tom66]

Re: Vizio VW42L HDTV10A - Just replace caps? or test PS?

The FR linked is low esr, not general purpose, and would be fine.
The ZLH you linked to is also fine.
Digikey calls them general purpose, but they aren't.

[Dgtech]

Re: Vizio VW42L HDTV10A - Just replace caps? or test PS?

Wow, we went from the set fell to replacing caps against the tech's advice that a fall could not have cause the caps to go bad - or the inverter board... It would be more like it that maybe a cable is loose, like the t-conn. Maybe a tab bond issue.
How about tell us about how it fell?
What direction it took the hit?
How high?

This is going to get you where you need to be instead of changing every part in the set. That could get costly.

[tom66]

Re: Vizio VW42L HDTV10A - Just replace caps? or test PS?

I am thinking if a bulb in the set was cracked due to a fall we would get 2 seconds to black not flickering.

It's almost certainly those caps that need replacing as we have seen the repeated flickering before when they go bad.

[awyatt2]

Re: Vizio VW42L HDTV10A - Just replace caps? or test PS?

i agree with tom i think the fall is unrelated to the problem. most of these sets have already been repaired at least once, if not its on borrowed time.look at the pics he posted offsite the cap bottom on one looks pushed out to me.this is a common failure in these sets due to a bad designed inverter board.