VIZIO E470VA Dead

[bwilliams60]

Re: VIZIO E470VA Dead

Good idea. I am going to knock off for the night. I will post back tomorrow after I have replaced it and tested. Thank you very much for your help. Very much appreciated and thanks to budm for your help. Good forum to belong to!

[budm]

Re: VIZIO E470VA Dead

Glad to hear that the hair dryer trick works for you (I was going to tell you to check the DCV on that cap but I think it was too dangerous for you to be working in the primary side based on how you were measuring the Voltage on the primary side in post 1, and I do not want you to get hurt or cause more damage if something bad happens). So you fixed the TV with 50 cents part and save lots of money and the TV from the landfill.

[retiredcaps]

Re: VIZIO E470VA Dead

I haven't looked at capacitor datasheets in probably 2 years now and was a bit surprised to find that the Panasonic FC 10uF 50V cap has the following characteristics.



Ripple = 125 mA
Impedance = 1.300 Ohm
Endurance = 1000 hours at 105C

The 1000 hours is pretty low. For every 10C decrease, endurance doubles. Thus,

1000 @ 105C
2000 @ 95C
4000 @ 85C
8000 @ 75C
16000 @ 65C
32000 @ 55C
64000 @ 45C

Now, my guess is that the average TV runs in the 55C range when ON. It might be 25C when in standby mode? If correct, that is roughly 5 to 6 years? The Vizio TV set you have might be 5 years old?

So I did a quick search for Rubycon and found

https://cdn.badcaps-static.com/pdfs/...4d451e9517.pdf

The Rubycon XJY has

Ripple = 100 mA
Impedance = 1.5 Ohm
Endurance = 5000 hours at 105C

meaning

5000 @ 105C
10000 @ 95C
20000 @ 85C
40000 @ 75C
80000 @ 65C
160000 @ 55C
320000 @ 45C

Now the ripple on the YXJ is slightly worse and impedance is slightly higher than the FC, but it might be on par or better than the original capacitor? What is the brand and series of the original? Samwha?

YXJ is slightly cheaper too (36 cents CDN at digikey.ca or 2 cents USD with current exchange rate - hahaha)!

Anyway, now that I'm aware of this, my future orders will probably go with YXJ.

PS. United Chemi-con KY series has exact same characteristics as Rubycon YXJ for 35 cents CDN at digikey.ca.

[bwilliams60]

Re: VIZIO E470VA Dead

Glad to hear that the hair dryer trick works for you (I was going to tell you to check the DCV on that cap but I think it was too dangerous for you to be working in the primary side based on how you were measuring the Voltage on the primary side in post 1, and I do not want you to get hurt or cause more damage if something bad happens). So you fixed the TV with 50 cents part and save lots of money and the TV from the landfill.

Thank you for worrying. Is there a post on here somewhere that details the best way to test the primary side of an SMPS? I know I should use an isolation transformer which I haven't got yet, but what else might I need to know? Thank you in advance for your help.

[bwilliams60]

Re: VIZIO E470VA Dead

And so, TV repair #1 is now under my belt thanks to budm and retiredcaps. You guys have provided excellent mentoring and the $0.50 cap ($0.10 US, lol) did the trick. Much obliged for the lessons and looking forward to some more down the road.
Now back to my own Samsung display that also appears to be dead and at a dead end on another thread.
Thanks for the help!

[bwilliams60]

Re: VIZIO E470VA Dead

I'm back. Perhaps I spoke too soon or perhaps I am just doing something wrong. So I plug the set in and a nice crisp screen comes up with the Vizio logo and I can pull up the menu (no remote) by pushing the buttons but I don't get any channels? I try to do an autochannel select and as soon as I go to start, it says it is done. Still no channels. I guess I should hook up another source (DVD ?) and see if it plays?
Question 2. When I do get this working, can I program a Universal remote to work with this set? Thank you in advance.

[budm]

Re: VIZIO E470VA Dead

The universal remote should work. Are you on cable or you trying to pick up the signal over the air?

[bwilliams60]

Re: VIZIO E470VA Dead

I am on cable and I checked my cable with another TV and it works fine. When I go to autochannel to program the channels, it goes from 0% to 100% instantly and says done and there is no sign of any channels.

[bwilliams60]

Re: VIZIO E470VA Dead

UPDATE:
Okay we are back on track. Apparently if you don't have a set top box and are just using normal cable, you need to set it to antenna. Did that and all good. Beautiful picture on this set.
Imagine, reading an owner's manual can help you solve some of life's smallest problems

[budm]

Re: VIZIO E470VA Dead

Good.

[bwilliams60]

Re: VIZIO E470VA Dead

Thanks again budm for checking in. Appreciate the help.

[bwilliams60]

Re: VIZIO E470VA Dead

I guess I did speak too soon. I have been turning this one on and off at random and now the same thing is going on.I turn it on, Vizio light may or may not come on and then nothing. Voltage on main caps is around 370VDC for a bit and then falls down to 162VDC. At this point, it won't turn on. If I heat up the area that we replaced the cap in, unit will come on and work. There is something there labelled FB108. Does anybody know what this is? Right side of power supply board in 5V section. Seems discolored.

[budm]

Re: VIZIO E470VA Dead

FB108 is more likely to be Ferrite Bead inductor, it should have <1 Ohms of resistance.

[bwilliams60]

Re: VIZIO E470VA Dead

I placed my ohmmeter across it and it does indeed have less than 1 ohm across it. In fact I can't even get a measurement on it it is so low but there is definitely continuity. Budm is there anything else in that section that may cause this and how can I test for it.
I have tested all the diodes cold and they are all okay (.522). I am ssuming because I am in the 5V section I can put my meter to chassis ground. Can I measure voltages to the VIPER KB2105 chip or the KT2222A/KTN2907A transistors or the three Everlight BC115 chips. I know when I warm that area for less than 1 minute, the TV will work fine afterwards.

[jetadm123]

Re: VIZIO E470VA Dead

Since the problem is heat related, maybe a bad solder joint? Try touching up the joints in the 5V section budm outlined earlier.

[bwilliams60]

Re: VIZIO E470VA Dead

I removed the board and inspected again. I still don't see any bad joints and I am posting pics. Perhaps someone else can see it.

[bwilliams60]

Re: VIZIO E470VA Dead

Bump

[Agent24]

Re: VIZIO E470VA Dead

Look again. There are some joints which look cracked - you can see a slight ring next to the arrows I have added.

Use your iron on all the through-hole component joints in that area an add a touch more solder to reflow all the joints.

Also try to upload JPG files as they can be previewed more easily.

[bwilliams60]

Re: VIZIO E470VA Dead

Good eye. I will reflow all the joints in that area and get back to you. One other thing I did was check the optocouplers and the one in the middle gave me readings on both sides in both directions where the two outside ones did not. When I say that, I mean both directions on the diode side and both directions on the transistor side. Would this be because it is in the circuit or should all three read the same?

[Agent24]

Re: VIZIO E470VA Dead

If they are all identical parts they should all have the same readings, but yes, in-circuit readings may be affected by other connected components so to test properly you'd need to remove and compare all of them out-of-circuit.