Ceramic capacitor

[lezsimply]

Hey guys. could you help me identify the value of this ceramic capacitor coz I search over the internet and found no real answer as to what the correct value is. This is from an 17 inch LCD monitor from HannsG. It has two of this but the other one got burned so I need to changed it. I would also want to know what may have cause for it to burn. Please see the images attached. Thanks

[ilkatek]

Re: Ceramic capacitor

Hello lezsimply
If a ceramic cap failed means that the voltage at its ends has exceeded the ranged voltage insulation. Some times they fail because the material has suffered stress over time and cannot handle the voltage peaks that some times may also occur. Anyway yours seem to be 5pF and insulation range of 3000 volts.

[lezsimply]

Re: Ceramic capacitor

thanks ilkatek. I examined the burned component and it revealed that it has a mark of "10 3KV SEC" The owner mentioned that it was previously repaired. I'm not really into lcd's but I think of it as and additional knowledge for me. What do you call this rectangle shaped component circled in orange? its the one conected to that ceramic and the other one is a resistor.

[ilkatek]

Re: Ceramic capacitor

I don't understand what component you mean but if its the one that connects both sides of the cap then most probably is some kind of transformer or most probably a coil which together with the cap creates some kind of oscillator. You say that the cap is 10pF but I don't know how you arrived to that conclusion, anyway even if you place a cap with close to those values, lets say 5pF to 15pf I think the thing will function without problems. Of course always better if you replace with same value as the original.

[stj]

Re: Ceramic capacitor

if you tried to post a pcture, you failed - use the attachement function to upload the foto.

[budm]

Re: Ceramic capacitor

""10 3KV SEC" "
That is just the ballast cap for the CCFL, 10pF 3000V.
They do fail due to the high Voltage breakdown.

http://www.mouser.com/ProductDetail/...8TXx1wJSYfA%3d

http://www.mouser.com/ProductDetail/...XgPAy5MifX0%3d

The one in the picture is 5pF.
You need to use the correct value since it will determine the amount of current flowing through the CCFL.

[lezsimply]

Re: Ceramic capacitor

Oh sorry I forgot to attach the pic. Here's the component circled in orange, I don't know what's it called.

There's another question, is there a possibility the that previous technician who worked on this didn't use the same value? Or maybe he did. The other is 5pf and the burned one is 10pf.

[lezsimply]

Re: Ceramic capacitor

Thank you very much budm. The link is very useful

[stj]

Re: Ceramic capacitor

in orange is the invertor transformer.

[budm]

Re: Ceramic capacitor

OK, looking at the connections on the bottom side, those two caps do not have the same value.
If I remeber it correectly, the 5 pf should be the one that is connected in parallel with the high Voltage winding of the inverter transformer as shown in the red circle in your picture:
https://www.badcaps.net/forum/attach...8&d=1442564246

The 10pF will be the other one in another location.
The 10pF is the one that burnt out, right?

[lezsimply]

Re: Ceramic capacitor

thanks stj. yes the burnt component is marked as 10 3kv sec. So what I need to do is acquire same value caps then put the 10pf one on the circled orange spot? thanks again

[budm]

Re: Ceramic capacitor

The picture #1 in post 1 is 5pF, so where did you get that 5pF from then?

[lezsimply]

Re: Ceramic capacitor

Here's where it was soldered circled in orange. I took it out so I can show it to a store and maybe they have same type, but sadly none was around.

[Shane711]

Re: Ceramic capacitor

Need help. I have a power board with 2 burnt 5pf 6.3kv caps and I want to replace them with higher voltage. This seems to be impossible. I know they are only going to blow again. So what can I do to modify this board where they can handle the work load? These 2 caps are for the CFL backlights.

Will adding a heat sink and cooling fan help? Not sure if these have failed from heat or over voltage but I would guess first it is over voltage.

[eccerr0r]

Re: Ceramic capacitor

What's the condition of the CCFL tubes, if they're bad it could cause this...

[Shane711]

Re: Ceramic capacitor

I have not opened it to find out. I will see if I get time to look at the CFL's