Help Identify Capacitor

[Gladiatorx]

Hello everyone I'm trying to identify the blue capacitor in the pic. I was at the electronics store today and they gave me the ones in the package also in the pics. They seem to be half the size of the blue ones in the board now. This capacitor comes out of a LED TV.

[R_J]

Re: Help Identify Capacitor

It should be ok, it is the right value and the voltage is 1kv, I would have used a 2kv if available but it should be fine.

[Gladiatorx]

Re: Help Identify Capacitor

R_J thanks the blue one blew the back out for what ever reason. So a 2KV would have worked also?

[budm]

Re: Help Identify Capacitor

It would be better to use 2KV, that is snubber cap and it is common failure cap.

[stj]

Re: Help Identify Capacitor

i seriously doubt those new ones are 1Kv,
they look too thin.

i never trust NTE, they started as a company buying obsolete/surplus parts and re-selling them with there own numbers on them.
a good excuse to sell a lookup-table.

[Gladiatorx]

Re: Help Identify Capacitor

well I must say I'm having difficulty finding these online

[Gladiatorx]

Re: Help Identify Capacitor

Not sure if I'm breaking a forum rule by posting a link. Here is what I found as far as USA stock, but these are 3KV.

Anyone comment?

[R_J]

Re: Help Identify Capacitor

Check digikey: Here is one 490-4168-ND
https://www.digikey.com/products/en/...=1&pageSize=25
or
https://www.digikey.com/products/en/...=1&pageSize=25

Some brands like Vishay are smaller, tdk are larger (and blue) its just how they are made

[Gladiatorx]

Re: Help Identify Capacitor

Thanks R_J is one brand better than another? I saw some cheap ones on amazon entire kits of 100 pieces and people complaining a failures and not within specs so figured don't bother.

Also when this cap popped I didn't see any other damage. I just did ohm readings on the nearby components.

[R_J]

Re: Help Identify Capacitor

Sometimes the fet can go also, if its not shorted, put one of the nte caps you have and try it. Then you will know. Its a snubber capacitor, its value is not that critical. If you want to replace it with a 2kv, any of those from digikey will be fine.

[Gladiatorx]

Re: Help Identify Capacitor

R_J think i can just use the NTE I bought as pictured in a previous post just as a test to see if the thing turns on? Then I'll go get the 2KV.

Or is that NTE not a snubber cap?

[R_J]

Re: Help Identify Capacitor

The capacitor is used as a snubber in that circuit, It is used to suppress any high voltage spikes created by the switching circuit. It protects the fet from any high voltage spikes that could damage it. The nte will work. its just good practice to to use a 2kv as it will handle the higher high voltage spikes.
the nte cap can be used anywhere in this case it is used as a snubber.

[PeteS in CA]

Re: Help Identify Capacitor

i seriously doubt those new ones are 1Kv,
they look too thin.

i never trust NTE, they started as a company buying obsolete/surplus parts and re-selling them with there own numbers on them.
a good excuse to sell a lookup-table.

As did Mouser. Back in really ancient times there was Poly-Paks, who I think bought up floor sweepings and reject bins. Long, long ago in a desert far, far away, Honeywell Phoenix had a warehouse where they sold all kinds of surplus parts. De Vry students loved the place (Dervy was on 24th St. and Highland Ave. at the time).

[stj]

Re: Help Identify Capacitor

poly-paks sounds like the packs of assorted shit radio-shack used to sell - the led ones had some interesting content!

[PeteS in CA]

Re: Help Identify Capacitor

Yeah, they were kind of a grab bag kind of thing. This was somewhere around 1970, when our school cafeteria was serving the last of the frozen dinoburgers.

[Gladiatorx]

Re: Help Identify Capacitor

Hi all well, replaced the cap and nothing. Checked some pins that lead to the logic board which have about 4 pins stating 13VDC, but nothing. Then went back to hot side of board, and the fuse is good, get 120V, checked a bridge rectifier, I get no AC or DC on it. On the hot side of the board, I get low voltages all around the board about 8.3 volts.

i attached some more pics of the board.

[Gladiatorx]

Re: Help Identify Capacitor

Attached is the bottom of the board

[R_J]

Re: Help Identify Capacitor

I am guessing this is a samsung board, bn44-00740a, If you have no a/c on the bridge you will not have any voltage at all, anywhere. are you sure your meter is working?
Check the fuse and then check VX801S
What are you using for ground when checking voltages on the hot side?
You also need to tell us which pins you are checking that have voltage "Some pins" does'nt mean anything.
I see that cap was just across a diode, I thought it was across a fet like on some power supplies

[Gladiatorx]

Re: Help Identify Capacitor

Yes correct it's a samsung BN44-00740A...maybe I should have started another thread under the TV troubleshooting?

So on the hot side I just used one of the board screws.

Not sure how to test that mov while it's in the board can that be done with a multimeter, I found not good youtube videos on those while in circuit

[R_J]

Re: Help Identify Capacitor

When checking DC in the primary, always use the (-) of the main bridge rectifier, that is refered to as HOT ground

Correction, The mov VX801S will check open, NT811S should check low (2.5Ω) I got mixed up looking at the top and bottom pictures.

To eliminate a bunch of checking, measure the DC voltage across the (-) and (+) of the bridge rectifier.
Next measure the voltage across the main filter CP811S
You said you measured 13 vdc on CNM803 plug, This voltage on the secondary CAN be measured to ground, You can check this voltage on any of the JP808-11 jumper wires.
If you have 13 volts, then Unplug the tv, disconnect CNM803 from the main board and plug in the tv and see if the backlights come on (they may or may not)