Capacitor noisy


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Capacitor noisy

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spike47
New User

Aug 14, 2009, 11:26 AM

Post #1 of 5 (1046 views)
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Capacitor noisy	Can't Post

HI

I have a conponent marked 103 1kv , I think it is a ceramic capacitor , it is off the power board section of a LCD tv PCB , there is a fault in that the red stand by light is flashing on and of and a small blue button capacitor as marked above is clicking away .
Question , what symtems could cause a capacitor to start making a clicking sound .

cheers

spike

Paulpablo
Enthusiast

Aug 14, 2009, 6:15 PM

Post #2 of 5 (1037 views)
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Re: [spike47] Capacitor noisy [In reply to]	Can't Post

No brand or model# = no help!

spike47
New User

Aug 14, 2009, 7:27 PM

Post #3 of 5 (1031 views)
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Re: [Paulpablo] Capacitor noisy [In reply to]	Can't Post

Hi

yes I didn't give much info , I have just posted a new thread with more info , I have tried to attach a photo and a drawing but it is only asking for a web address !! .

cheers spike

rrobor
Veteran

Aug 16, 2009, 8:02 AM

Post #4 of 5 (1013 views)
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Re: [spike47] Capacitor noisy [In reply to]	Can't Post

Had 2 capacitors noisy once, They were touching very lightly and at a certain temperature they made a noise like a demented cricket. I remember it well all these years later, doubt if Ill ever get another.

tscheucher
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Aug 17, 2009, 5:10 PM

Post #5 of 5 (1001 views)
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Re: [spike47] Capacitor noisy [In reply to]	Can't Post

Hello spike47!
It�s nothing special then we know as ceramic disc capacitor for high voltage.
Its value is printet on it�s surface -
103 means:
10 + three times zero (000) and the value is given in pF = 10.000pF = 10nF
1kV = 1000V = The components maximum threshold voltage --> So you�ll have to buy a ceramic disc capacitor with 10nF and 1000V --> Better use 2000V type because these clocked voltages in primary stages of switching power supplies can exceed 1kV at startup.
I assume it�s in parallel with a coil (with or without sinter iron core) or a choke.
To your second question:
Your capacitor for sure had been overheated and so the dielectric failed, wich made it easy for high voltages to spark between the two plates of the capacitor and it caused short circuiting (or nearly short circuiting) inside of it. The sourrounding air expands due to these sparks which are present (discharging phenomen) while operation and that makes the clicking sound or worst case: The faulty cap caused short circuiting somewhere on the pcb. (Who knows without a schematic)
You�d better replace the defective components before the TV (or audio device) takes serious damage.
cheers too
Thomas

(This post was edited by tscheucher on Aug 17, 2009, 5:12 PM)

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