Another VW42LHDTV10A no picture, no sound

[mrhanso]

Hi,

Been following your threads for a while and amazed at how much I've learned already. I have a Vizio VW42L where a get no picture or sound. Based on the previous threads I've read on this model, I'm thinking its a bad main board or power supply / capacitor. My case is a little more unusual than the others.

Here are the symptoms.

1) When I plug the TV in, the Vizio LED glows orange
2) When I press the power switch (on remote also), the LED goes to White
3) The LED stays white for exactly 43 seconds, then goes back to orange.
4) At exactly 7 seconds after pressing the power switch, the LCD panel blinks, then goes back to black.
5) Also, at 7 seconds, the blue LED (MD1) on the Master Inverter blinks and goes off
6) I get 5.25v on the Power Supply CN4 Pin1 when switch is on or off
7) I get 1.948v on the Power Supply CN4 Pin13 (PSON) when switch is on.
8) All fuses on PS, Main Board, and Inverter board are good.
9) Fuse F1 on Main Board is 5.23v when switch is off or on
10) I get nothing on F2 on Main board when switch is off or on (seems odd)
11) On Master inverter fuse F1 I get .67v when switch is on.
12) On Slave inverter fuse SF2 I get .65v when switch is on.
13) The voltage main board regulator numbers don't match the other threads I've read on this model TV. My G1084 LDOs are V20, V19, and V15. Here are their readings in GR/VO/VI order:

V20: .569 / 1.814 / 3.277
V19: 1.270 / 2.527 / 5.14
V15: 2.06 / 3.30 / 5.13

14) Upon visual inspection, the 330uF, 35v cap on the Power Supply is bulging (see attachment). I took it out and was able to test it on a DMM that only goes to 200uF. It took a charge and went to OL after a few seconds. I ordered a new one and will replace it, but haven't received it.

I hope that is enough for you to help diagnose?

Thanks,
Mike

[retiredcaps]

Re: Another VW42LHDTV10A no picture, no sound

Here are the symptoms.

10) I get nothing on F2 on Main board when switch is off or on (seems odd)

Thank you for a great detailed description. It makes helping you a lot easier.

Not getting any voltage on F2 might be due to the bulged cap. Normally, United Chemicon makes good caps. If I recall correctly, it is a KY series which is a good series, but from other threads that one particular cap always is bloated for some reason. It could under a lot of stress?

11) On Master inverter fuse F1 I get .67v when switch is on.
12) On Slave inverter fuse SF2 I get .65v when switch is on.

Your inverters require way more than less than 1 volt.

13) The voltage main board regulator numbers don't match the other threads I've read on this model TV. My G1084 LDOs are V20, V19, and V15. Here are their readings in GR/VO/VI order:

V20: .569 / 1.814 / 3.277
V19: 1.270 / 2.527 / 5.14
V15: 2.06 / 3.30 / 5.13

Those output voltages look okay, but it depends on the part number. For example, an AL1117-33, where the suffix denotes the output voltage, will output 3.3V DC +/- 1%.

14) Upon visual inspection, the 330uF, 35v cap on the Power Supply is bulging (see attachment). I took it out and was able to test it on a DMM that only goes to 200uF. It took a charge and went to OL after a few seconds. I ordered a new one and will replace it, but haven't received it.

I hoped you ordered a low ESR cap. Something like Panasonic FR or FM series.

I hope that is enough for you to help diagnose?

Again, a great description and thourogh job.

[mrhanso]

Re: Another VW42LHDTV10A no picture, no sound

I'm honestly not sure what brand of caps I bought. I matched the uF, voltage, and temps. I picked them up on ebay for 5 bucks. Will these suffice?

[retiredcaps]

Re: Another VW42LHDTV10A no picture, no sound

Will these suffice?

For test purposes only, maybe. Caps on ebay are generally poor quality or fakes.

For long term reliability, this is the proper cap.

http://search.digikey.com/us/en/prod...2413-ND/613774

[budm]

Re: Another VW42LHDTV10A no picture, no sound

Can we get good closed up pictures of the power supply board connectors so we can see the labels on them? Also goo closed up pictures of the borrom side.
Is it FSP brand, model number as shown on the board?

[tom66]

Re: Another VW42LHDTV10A no picture, no sound

ChangX - I see them on some Vestel sets but they are generally pretty poor caps. They are just the cheapest caps available as they don't make their own caps, they just stick their name on whoever bids the lowest. Inconsistent quality is probably worse than poor quality.

Now that cap isn't just failed it's really badly bulged, which is rare. And it looks like a Chemicon which is generally a good brand. It could have been a fault with the power supply - like a rail voltage going too high. That's quite rare though. But it looks like it's under a heatsink, so that could have been the cause.

[retiredcaps]

Re: Another VW42LHDTV10A no picture, no sound

I picked them up on ebay for 5 bucks.

It would also help if you filled in your profile with at least the country information so we can suggest suitable suppliers rather than ebay.

[mrhanso]

Re: Another VW42LHDTV10A no picture, no sound

Thanks all for your input.

I'll make sure I replace the cap with the one you show on digi-key once this thing is up and running. For now, I'll assume the ones I ordered will do for testing purposes. I attached some closer pics of the power supply. The model is a FSP254-3M01 Rev 1. I also took a pic of the PS bottom. Keep in mind, the solder job on the Mosfets was done by me after I tested them. I will also neaten that up afterwards if I don't end up buying a whole new board.

[retiredcaps]

Re: Another VW42LHDTV10A no picture, no sound

I'll make sure I replace the cap with the one you show on digi-key once this thing is up and running. For now, I'll assume the ones I ordered will do for testing purposes.

If the ebay caps are coming from Asia, you can order from digikey and pay $2.75ish USD for first class postal service and get the proper cap in about 2 to 3 days.

[mrhanso]

Re: Another VW42LHDTV10A no picture, no sound

Thanks again retiredcaps for your fast response. I always filter my ebay searches for US only. These are coming from Florida from a reputable seller and should be here tomorrow. Hopefully, they'll make due for now ... I have 5 to try! I'll put in an order for the panasonic ones also.

[mrhanso]

Re: Another VW42LHDTV10A no picture, no sound

Well, it looks like my project just got a bit more complicated. Upon further review of the inverter boards, it looks like all four caps are bulging and two have even leaked? Is it possible that the bulging cap on the power supply caused this ... or vice-versa?

Also, there are no markings on these caps, however I read some blogs that say they are 470uF 35v? Are the markings underneath and are they replaceable? A quick search on Ebay is showing refurb inverter boards for $60 each! Not the direction I was planning on going.

Is Digi-key the place to get these caps also? Is it Part# P13130-ND?

[selldoor]

Re: Another VW42LHDTV10A no picture, no sound

Its just heat, age and possible poor manufacturing.
take them off the board - they will have to come off anyway.
It should say what they are on the other side if not come back and we can research it.
We dont know at present if the digikey ones are correct - what physical size are the
they. Height - Diameter.

[mrhanso]

Re: Another VW42LHDTV10A no picture, no sound

OK, I took the board off and can read the detailed information on the back. Looks like a 680uF, not a 470uF like I thought. They seem to be 10mm x 22mm.

Also, i might be getting a little paranoid, but I really started inspecting every cap for any type of bulge. I think I found one on the power supply with a very slight bulge, so just to be safe, I'm going to replace that one also. That one says Rubycon, 25v 470uF Y X G and looks like it measures 20mm x 7mm?

[selldoor]

Re: Another VW42LHDTV10A no picture, no sound

A lot of the members subscribe to the idea that if some of the caps on the power board
have gone it is appropriate to change them all and get a clean start. It also means that if if later you find another cap is no good you save postage which could pay for a few caps.
I'd price them up and see.
Renewing some sometimes puts pressure on the old ones that are left.

[budm]

Re: Another VW42LHDTV10A no picture, no sound

I agree with selldoor, why take apart 2 or 3 more times because other caps failed later on. You replace them as a set with good caps so you will not have to deal with it for years unless other components failed.

[mrhanso]

Re: Another VW42LHDTV10A no picture, no sound

Ok, so based on your advice, I'd like to recap the inverter boards and the power supply. Looks like I've already ordered the cheapies and don't want to use them. Using the readings on the caps I want to replace, I used your advice and searched digi-key for panasonic FM series caps. Here is my list:

Qty Part Number Description
1 P12413-ND CAP ALUM 330UF 35V 20% RADIAL
4 P12417-ND CAP ALUM 680UF 35V 20% RADIAL
3 P12405-ND CAP ALUM 1000UF 35V 20% RADIAL
3 P12389-ND CAP ALUM 470UF 25V 20% RADIAL
3 P12366-ND CAP ALUM 1000UF 16V 20% RADIAL
1 P12386-ND CAP ALUM 330UF 25V 20% RADIAL

As you can see, I don't know too much about ordering caps, so can someone verify that I'm on the right track here? I tried to measure each cap size and use the closest mm size available ... do they have to be exact?

Thanks again for all of your help!

[tibimakai]

Re: Another VW42LHDTV10A no picture, no sound

those inverter boards look very familiar, recently I have replaced the chip and the four fet transistors on the slave board. Measure the fets across and see if do you read ~8.5k, if less then most likely the chip or maybe even the fet it's gone. On Ebay they sell this kit.

[selldoor]

Re: Another VW42LHDTV10A no picture, no sound

The two you have advised detail of are ok
BUT size wise unless they are an exact match only you can tell.
If it is under a heatsink 3 mm difference in height might mean it is touching so no good. Diameter wise if you have a lot bunched together and each one is 2 mm fatter it will be struggle to get them in.
Having made your choice of caps go back and see where they are and check
if the space/height is an issue.

The Digikey part numbers are correct for the voltages & uf stated alongside
so if that description is from your list and not from the digikey site and the size is ok as explained above you are good to go.

[mrhanso]

Re: Another VW42LHDTV10A no picture, no sound

Ok, seems like there is plenty of room if I'm off a mm or two.

I noticed on the inverter boards, the solder is on the top and there are no holes to put the leads through. Any tips or techniques on how to solder the new caps on the board?

Hopefully, there is nothing wrong with the chip and fets because I think that solder work is out of my league. lol.

[retiredcaps]

Re: Another VW42LHDTV10A no picture, no sound

A lot of the members subscribe to the idea that if some of the caps on the power board
have gone it is appropriate to change them all and get a clean start.

The "change them all out" recommendation also is an economic one. In order to test the ESR (ohms) of a cap, you need an ESR tester which costs anywhere between $60 to $300. To check the ripple output, you need an oscilloscope which starts at around $400.

Unless you are in the repair business, it is cheaper for the "one time" DIY person to just change out all the caps for less than $20. Now if caps were $5 each instead of 50 cents, it might be a different story.