what could be the problem of our crt tv??? Specifically it is a Samsung brand 21 inch tv,, we can still watch the tv and it works normally but ,, when i power on the television a"ssssss" sound will be heard or as if it is like a spark or leak sound of air,,but if I turn-off the tv again the sound will stop,,

when i opened the back of our tv i haven't seen anything like spark,,,
what could be the problem? any suggestion pls??

 

It could be a bad solder joint in the primary power supply part or a problem with the HV transformer. If you didn't see anything sparking when you opened the TV it may be a bad contact somewhere on the bottom of the main PCB.

If you have no experience with electronics don't do anything, ask a technician. Otherwise, try to have a look at the bottom of the PCB and look for any bad contacts. Make sure the primary high voltage capacitor is DISCHARGED before sticking you fingers in the TV set.
I attached some examples.

 

Wow, I've never seen a picture of a bad solder joint. I always thought they were microscopic. I would just reflow solder on everything to make sure it was all good.

 

It might be the problem of CRT base (the socket which connect the CRT Board to CRT pins).What I am talking is like this ,when you turn on the TV it will sound ssssssssss after some time when the TV gets warm up the (sssssss)sound will disappers slowly.

But as praondevou said,if you don't know much don't mess with it rather ask a technician.

Good Luck

 

Turn the lights off and look for a corona discharge. When dinosaurs roamed the earth, we used "corona dope" to suppress such things. Sometimes a high voltage wire had been damaged and leaked energy. For that, you replace the wire.

Standard warning: It takes several thousand volts to produce a corona leak. If that's your problem, you're in very dangerous territory trying to fix it.