Vizio VO42L FHDTV10A No Power

[retiredcaps]

Re: Vizio VO42L FHDTV10A No Power

Hopefully the regulars will be here soon to point you in the right direction from here

1) Why? You are doing a great job.

2) BTW, now you understand why we always INSIST on good quality pictures of the OP's board and not some stock photo or reusing other people's photos. Without the OP's board photos, you would have never spotted all those burned out components.

3) I would also check BD1, the bridge rectifier, for shorts. Number the pins 1, 2, 3, and 4. Measure the resistance between pins 1-2, 1-3, 1-4, 2-3, 2-4, and 3-4. Any reading under 30 ohms suggests a short and must be desoldered and retested out of circuit.

4) I would also suggest recapping this entire power board. Since you got this TV for free, recapping the entire power board will probably be less than $15 USD. Poor quality caps will allow too much ripple into the components.

What are the original cap brand and series?

[Xecuter]

Re: Vizio VO42L FHDTV10A No Power

Thank you so much bbjunkie. With your help I'm finally making progress.

I can only find 1 fuse and it's the F1 fuse which has no resistance on it. When I test for continuity my meter beeps. Should be ok, right? I think it has a black heat shrink wrap over it. Is that what you meant, selldoor, by being black?

[bbjunkie]

Re: Vizio VO42L FHDTV10A No Power

It may still be high resistance. The only 99.9% sure way of making sure the fuse is good is to do a resistance test on it.

First of all put your meter on the 200 ohm setting and touch the probes together, note the reading. Then, test the resistance of the fuse - take the first measurement from the resistance shown for the fuse, your result should be less than 1 ohm.

Why? You are doing a great job.

Gee, thanks!

[retiredcaps]

Re: Vizio VO42L FHDTV10A No Power

I can only find 1 fuse and it's the F1 fuse which has no resistance on it. When I test for continuity my meter beeps.

A good fuse should measure less than 1.0 ohms (with power off and lcd unplugged). NEVER use the continuity for this type of check. Some multimeters beep "continuous" for readings under 1800 ohms. Any fuse that reads 1799 ohms will CERTAINLY be bad.

From my "2 seconds" page at

https://www.badcaps.net/forum/showpo...4&postcount=19

If you have a manual range multimeter, set it to 200 (two hundred) ohms. Touch the black and red probe together. It should read between 0.1 or 0.5 ohms. If it is higher than 1.0 ohm, there is something likely wrong with your multimeter. Either the test leads are frayed internally and/or the battery is dying which will result inaccurate readings.

If your multimeter reads "1" or "0L", it means the measurement is outside your chosen range. Don't confuse "1" on the left hand side of this display with 1.0 on the right hand side. The first means out of range and the second means 1.0 unit of your measurement.

[retiredcaps]

Re: Vizio VO42L FHDTV10A No Power

Xecuter, take time to read post #18 and onwards. Sometimes a lot of overlap and edits happens so you might miss some important information when there are too many cooks in the kitchen.

Back to mode.

[selldoor]

Re: Vizio VO42L FHDTV10A No Power

too many cooks in the kitchen.

Back to mode.

Well 1 cook less - I'm off to bed - goodnight

[Xecuter]

Re: Vizio VO42L FHDTV10A No Power

Thanks for the heads up on the edits. I did notice them and have re-read all posts.

So far I know that the power mosfet stp9nk70zfp is no good as well as a couple other resistors.

I went ahead and checked the fuse again as recommended and the results are in the attached pictures.

As far as the bridge rectifier, I hope I tested it correctly as I tried different combinations of pins like it was suggested. Nothing was under 30 ohms.

[retiredcaps]

Re: Vizio VO42L FHDTV10A No Power

I went ahead and checked the fuse again as recommended and the results are in the attached pictures.

As far as the bridge rectifier, I hope I tested it correctly as I tried different combinations of pins like it was suggested.

Your fuse is good.

As long as all the pin combinations (6 of them) are much greater than 30 ohms, BD1 is likely good.

It looks like you have a Hakko FX888. I'm jealous!

[Xecuter]

Re: Vizio VO42L FHDTV10A No Power

OMG you just made me blush. Sadly though, it's not a hakko although I do wish I could afford their lovely products. It's just a chinese Yihua 899D. Works perfectly well I must add.

Now that we've identified faulty components, has the mystery been solved? Or is there likely more faulty components to be found? Also, does anyone have the schematics to the power supply board as I can't identify the value for the resistor in R206?

[retiredcaps]

Re: Vizio VO42L FHDTV10A No Power

It's just a chinese Yihua 899D.

Wow, I could have sworn the blue/yellow color scheme was Hakko, but then I just saw the very lower part of it.

Now that we've identified faulty components, has the mystery been solved? Or is there likely more faulty components to be found?

I think we have covered the most likely things. When the new components arrive, do the same tests BEFORE installing them to make sure they are all okay.

Also, does anyone have the schematics to the power supply board as I can't identify the value for the resistor in R206?

Try

http://elektrotanya.com/

If not, try cleaning the resistor with some isopropyl alcohol to see if the colors show up?

[bbjunkie]

Re: Vizio VO42L FHDTV10A No Power

<deleted>

[Xecuter]

Re: Vizio VO42L FHDTV10A No Power

Yes, it is a blue/yellow color scheme. Part of the reason why I got it (hakko ripoff, I know).

Trying to read the resistor is a no go. It's missing a nice chunk in the middle which means there is nothing to read.

[bbjunkie]

Re: Vizio VO42L FHDTV10A No Power

There's another thread going at the moment with a VO42L - i've posted there to ask the owner to check his psu for the values.

See https://www.badcaps.net/forum/showthread.php?t=18294

[caphair]

Re: Vizio VO42L FHDTV10A No Power

Very interesting to see a number of components burnt/shorted in this. It's somewhat similar to the problem my Vizio (different model number) experienced. I ended up replacing entire power supply because it was cheap enough $20

Here's the thread I had made about it, you can clearly see burnt components.

https://www.badcaps.net/forum/showthread.php?t=18080

[bbjunkie]

Re: Vizio VO42L FHDTV10A No Power

Out of curiosity, what does R206 measure now?

probably open circuit seeing as the fuse didn't blow. If however it went s/c first then it may have taken ic201 with it, perhaps retiredcaps could correct me if im wrong.

[Xecuter]

Re: Vizio VO42L FHDTV10A No Power

The readout for R206 is in the picture.

R202 only shows a (1) on my meter.

Does anyone know what kind of resisters these are so I may find replacements?

IC201 also has me worried, as bbjunkie mentioned, it might be damaged. Is there a simple way to test this?

[bbjunkie]

Re: Vizio VO42L FHDTV10A No Power

Not definitive but you could check the vcc pin for short to ground it won't tell you it's good but may tell you if it's bad.
You will need to get the number of ic201 and search google for a datasheet then look on that for the pin out listing. Measure resistance from voltage supply pin to ground.

I'm off to bed, 2.50am here in the UK now!
Good luck

Jim

[Xecuter]

Re: Vizio VO42L FHDTV10A No Power

Could someone help me identify the two resistors that are in the attached photo which are R206 and R202.

I need to replace these and I would like to know their specs.

I believe that:

R202 is a 0.47 Ohm +/- 0.5% metal film resistor, but I don't know the watt rating.

R206 is a 3k Ohm +/- 5% carbon film resistor, and I also don't know the watt rating.

[selldoor]

Re: Vizio VO42L FHDTV10A No Power

Im not so sure about those values.
R202 based on Yellow Purple silver gold ie first 4 rings would be correct but it has additional ring/rings - other end has a black ring and is there another ring between
the black & gold
R206 seems to be correct if the colours are orange black red gold but I have difficulty
telling orange from red.
Might be safer to wait and see if a schematic is found. I have been looking but no luck so far - the "Key" to finding the power supply seems to be 0500-0505-0450 the number off the label rather than the E number off the board.
Regarding wattage I dont know but if not printed on seem relative to size see http://www.bcae1.com/resistrs.htm - looks like the small one might be .125 watt
and the larger one 0.5 watt. If you are going for a full recap there are more under the heatsinks.

Hah! a little bit nearer but not the info we need :http://www.fspgroupusa.com/fsp2543m01/p/832.html

They also have a technical help desk! perhaps they will tell you details of the burnt out resistors, though I
suspect they will come with the no user servicable parts rubbish.
http://www.fspgroupusa.com/support_center.html

[Xecuter]

Re: Vizio VO42L FHDTV10A No Power

So I took another look at IC201 on the back side of the psu and it turns out I missed a fracture line on the IC. bbjunkie was right as he mentioned in post 18.

Now that I know that it needs to be replaced, I can't make out the part number. The numbers I do see are FAN7602.

Does anyone know what this is and where to get it?

Also, could this IC have damaged any other components?