Trying to locate this safety cap

[repair-it]

I believe this is an x2 1uf 450v but not 100% sure. Tried to locate one and didn't have much success. Is anyone familiar? These are on a power board from a Vizio set.


thanks,
rich

[stj]

Re: Trying to locate this safety cap

its not X2 or it would say so - although it probably should be!

[petehall347]

Re: Trying to locate this safety cap

1uf film

[R_J]

Re: Trying to locate this safety cap

What is wrong with the cap? it is likely ok.

[repair-it]

Re: Trying to locate this safety cap

I have one that failed open, tested out of circuit. As I stated, I know what it is, just not able to locate a replacement other than 400v.

[PeteS in CA]

Re: Trying to locate this safety cap

As stj said, it's not an X2 rated capacitor. If it were it would be covered with safety agency approval markings. Maybe look into 630VDC rated film capacitors. 450V is an odd rating in my experience.

[R_J]

Re: Trying to locate this safety cap

It is just a film cap across the bridge rectifier DC side, to suppress high frequency from the pfc circuit. But if you want a link to the original, here is one:
Here is a link to the original https://www-taobao-com.translate.goo...o=ajax,sc,elem
They call it a safety cap but is not.
Digikey has lots of 1µf 450vdc film caps

[repair-it]

Re: Trying to locate this box cap

ok, thanks for that info. I'm curious how you found it (China original). I tried for hours on Google.

I was considering the higher voltage version and maybe an X2 version. I have one of these that is open on the AC side and wasn't sure it was contributing to the flickering back light shut down issue, so I was considering my options as I go down the rabbit hole on this one. Possibly the IC LED driver is bad. 3 supposedly good boards - weren't- and when I finally got a good working one, I'd like to figure out where the fault is on the original since the good board fix the flicker issue.

[bestsystem]

Re: Trying to locate this safety cap

May be this is a cost down safety cap without proper certification approval, a sign of Chinese cost down product.

[stj]

Re: Trying to locate this safety cap

backlight issue is almost always the leds going bad.

[repair-it]

Re: Trying to locate this safety cap

Yes, that was my first thought but they tested ok (tester isn't a guarantee) the behavior when the set was turned on seemed more like a shut down due to an over voltage (short) condition and once I put a working power board in, that cured the back light problem. LED driver IC is built into the power board and it may have failed on the original board, still testing that board for faults and comparing it to the working board. Legitimate working boards for this set are in high demand & hard to come by.

[televizora]

Re: Trying to locate this safety cap

As stj said, it's not an X2 rated capacitor. If it were it would be covered with safety agency approval markings. Maybe look into 630VDC rated film capacitors. 450V is an odd rating in my experience.

450v is not odd rating at all. 230x1.44(square root 2) means that the amplitude of the voltage in 230V AC grid(230v effective) can go up to 331.2V. If the device is not region specific and can operate from 120 to 240V, then 450V is ideal capacitor voltage. In worst case scenario can be eventually replaced with 400V if you know that the peak voltage wont go beyond 380-390V

[stj]

Re: Trying to locate this safety cap

but what if it has a pfc voltage booster?

[televizora]

Re: Trying to locate this safety cap

but what if it has a pfc voltage booster?

1. The capacitor which the author mentioned is most likely input noise filter capacitor. Have to see a picture of the whole board.
2. There are different types of PSU-s. There are quite a lot with serious PFC circuits, other are with much simpler design.
There are PSU-s with simple filter capacitors after the rectification stage, there are some with serious APFC circuits.
In some cases 450V can be replaced with 400V. In other cases - it cannot be replaced with 400V. Depends.
If PFC voltage booster is used, then 450V is a must and cant be replaced with 400V.

[TechGeek]

Re: Trying to locate this safety cap

This is very likely an RFI filter cap. Open filter = excessive line noise. Excessive line noise = weird and generally bizarre behavior, up to and including microprocessor lockups, watchdog timeouts, and/or firmware corruption. Change the filter and see if problems disappear.

[repair-it]

Re: Trying to locate this safety cap

Figured out the 'flickering back light' issue. The Regulator shunt AS431BZ was bad. It was almost the last component to be tested as I went down the rabbit hole on this one - a good lesson though.🤔 Vizio e601i-A3. Board dated 7/13/12. Unfortunately, the panel is/went bad.

[stj]

Re: Trying to locate this safety cap

interesting,
i'v never seen a 431 fail personally.

[repair-it]

Re: Trying to locate this safety cap

Well, if I tested it properly? As suggested in this article - I did get a small reading when I tested the last step. I assume when he says no reading, my meter should not move at all?

https://jestineyong.com/how-to-test-...gulator-tl431/

[Per Hansson]

Re: Trying to locate this safety cap

Well if replacing the TL431 got your device working again it can be a safe bet that was it.
But if you are interested in testing it properly you need to build a small circuit with it.
This was the simplest one I managed to find with a quick search:
https://diodnik.com/en/kak-proverit-tl431/

[repair-it]

Re: Trying to locate this safety cap

Interesting...thank you, always learning.