Help Identify Capacitor

[Gladiatorx]

Re: Help Identify Capacitor

DC across + & - rectifier - nothing

CP811S voltage - nothing

for 13V on plug CNM803 - never did get anything from the beginning even before I changed the snubber capacitor

[Gladiatorx]

Re: Help Identify Capacitor

VX801S testing resistance measure 478.4K

NT811S 3.7-3.8 ohms

[Gladiatorx]

Re: Help Identify Capacitor

By the way in the attached pic isn't one of those suppose to be standby power? Not sure with the marking which it is.

[R_J]

Re: Help Identify Capacitor

If you have NO dc across the bridge rectifier I will bet your main fuse is open.
with your meter on ac volts, check the voltage right where the plug connects to the board, then check across ~ & ~ of the bridge

[Gladiatorx]

Re: Help Identify Capacitor

at the main fuse 124Volts. At rectifier No AC voltage

[Gladiatorx]

Re: Help Identify Capacitor

So I must be doing something wrong, negative lead on one side of fuse, positive on other i get 124V

But using ohm meter it shows OL

[R_J]

Re: Help Identify Capacitor

which side of the fuse? both sides?
Ok, here iss what you do, check the ac voltage across CX801S, next across CX802S

I marked the path of the A/C voltage, check between the white and black lines and tell me where you loose the voltage

[Gladiatorx]

Re: Help Identify Capacitor

I tested as you see in the below pics. CX801s, can't get to the pins from above the board.

One pic shows me testing voltage the other ohms

[R_J]

Re: Help Identify Capacitor

Your fuse is OPEN !!!

[Gladiatorx]

Re: Help Identify Capacitor

how come it reads voltage the way I have the meter hooked to it?

[R_J]

Re: Help Identify Capacitor

Because the fuse is open, That is just phantom voltage, the ac is likely being coupled through CX801S, or the 3 resistors RX9-35,25,15, and shows up on the other side of the fuse.
Remember a fuse is basically just a piece of wire,
To check voltage properly you need to be able to access the other side of the board, then with one probe on [N] a/c neutral, you probe across [L] line, thats how you check for a/c voltage, the next step would be to leave one probe on [N] and probe each side of the fuse. then you would see there is a/c voltage on one side but nothing on the other side of the fuse. resulting in... open fuse

Because the meter does not really draw any current from the circuit, there will be no voltage drop across those 3 resistors, so the full 120vac shows up across the open fuse

[Gladiatorx]

Re: Help Identify Capacitor

Got itok got the fuse out confirmed blown. This say T 5AH 250V

That a slow blow fuse? Also I assume you can buy these with the leads on them so you can solder it back in. That's what these look like they are

[Gladiatorx]

Re: Help Identify Capacitor

By the way thank you again for hanging in there with me...hopefully I'll find the fuse in the morning and go from there.

Question is why did it pop

[R_J]

Re: Help Identify Capacitor

Yes, slow-blow (time delay) 5 amp, 250vac, pigtail 5x20mm
Digikey F3587-ND will work
Why did it pop? .... because that cap shorted. If you want to try the power supply, you can connect a 120 volt incandescent 60-100w light bulb in place of the fuse, the light bulb should light briefly, then go dim, If it stays brightly lite, there could still be a problem in the power supply

[Gladiatorx]

Re: Help Identify Capacitor

Hi good morning, so the only thing I could find at the local electronics store were 5A 125V pico type fuse. would these hold to test the board or would they immediately pop?

[R_J]

Re: Help Identify Capacitor

It should work for a test but pico fuses are usually fast blow, give it a try. maybe disconnect the plug to the main board and see if you get the 13 volts, without the main connected it will limit the current. If you get the 13 vots, unplug the tv, connect the main and try the tv

[Gladiatorx]

Re: Help Identify Capacitor

No blow right away

I curious on the bridge rectifier here is my test:

Tested in diode mode.

test on ac pins gives me - .976V

Red probe on + black on ac pins gives - .488V on both ac pins

Black probe on + black on ac pins gives - .488V on both ac pins

Not sure if or how you test the rectifiers + & - dc outputs

[R_J]

Re: Help Identify Capacitor

a bridge rectifier is nothing more than 4 diodes in a single package
forget about the bridge, If you pluged it in and the fuse did not blow the bridge is ok.
Did you get the 13 volts I asked about?

[Gladiatorx]

Re: Help Identify Capacitor

plugged it in and the fuse blew right away, so could not get 13V

[R_J]

Re: Help Identify Capacitor

Did you have the main board connected when you tried it?

Thats why we use the light bulb is series with the a/c input to limit the current, Start by checking the diode and the fets in that circuit where you replaced the cap.
check the resistance across the + & - of the bridge to see if there is a short, use regular ohm setting not diode test.
Check diodes dp802,dp803,dp808c, fets, QP801CS, QP811CS


It could be the fuse could not handle the surge of current and blew