Technika LCD42-910 Buzzing PSU

[Wabby]

Hi Guys,

Recently stripped down a LCD42-910 that is making a buzzing noise.
Straight away saw 3/4 caps that were bulging - One with a hole! Result, or so I thought.

Swapped them out, and still have the noise.

Anybody any ideas?

Im assuming its to do with those diodes up the top, but have no idea how to test them, and they show values in BOTH directions :S

[sordids999]

Re: Technika LCD42-910 Buzzing PSU

Take one leg of the diode out of circuit and measure again,and im thinking the buzzing noise is coming from the picture i have uploaded ?

[Wabby]

Re: Technika LCD42-910 Buzzing PSU

Yes from that area. Any ideas?

I will pull the diodes out and test.

[Wabby]

Re: Technika LCD42-910 Buzzing PSU

Top left circled area ish. Could also be coming from the 3 components under the heatsink in the middle at top

[Wabby]

Re: Technika LCD42-910 Buzzing PSU

Anybody else any bright ideas?

TV works perfect, just this very faint humming noise gets annoying when you 'hear' it because once you have heard it, you cannot unheard it. lol

[Wabby]

Re: Technika LCD42-910 Buzzing PSU

Checked and everything seems fine - Shame about the buzzing still though

[ReeceyBurger123]

Re: Technika LCD42-910 Buzzing PSU

These power supplies do hum because of the poor feed back and oscillation trust me you think thats bad wait till you hear a 17pw25-4 that sounds like a fucking car on a bad day they are the worst, its probably fine yes it might hum but just take your mind off it and dont obsess over it thats when you will notice it. My plasma buzzes and I used to obsess over it but just ignore it recap it fully with good caps for safety you never said but does the set work ?

[stj]

Re: Technika LCD42-910 Buzzing PSU

wax or epoxy covering the coils may help.

[Wabby]

Re: Technika LCD42-910 Buzzing PSU

Yeah set works fine.

Will epoxy damage anything?

[ReeceyBurger123]

Re: Technika LCD42-910 Buzzing PSU

Epoxy will be fine on the transformers will just muff out the buzzing noise as they normally are the cause.