Samsung UN46F6800 LED TV Buzzing and Vibrating on Startup

[jj777]

Hello, I am trying to fix a Samsung UN46F6800 LED TV. The issue is the power supply board makes a vibrating and buzzing noise for couple minutes after startup.

I've recorded a video of the noise here.

After 3-5 minutes, the noise goes away and everything on the TV works fine.

I took the back off the TV and closely inspected the power supply board, paying close attention for any bulged electrolytic capacitors. None of the capacitors look bulged or blown.

If I power the TV up with the back off and use a wooden pencil to try and pinpoint the source of the noise, it looks like the components circled in the red, blue and green on the image are where the noise is the loudest.


I am not an expert in TV power supplies, but my guess is that these components are part of the EMI circuitry.

Although these components seem to vibrate the loudest, I am not sure if they are the root cause of the vibration.

Does anyone have any ideas of what the root cause of the issue could be? Why does the noise disappear after 3-5 minutes after startup? Do you have any suggestions as to how I can further pinpoint the root cause of the issue?

Thanks!

[nomoresonys]

Re: Samsung UN46F6800 LED TV Buzzing and Vibrating on Startup

Prolly coil whine from your coils there, here's a little article for shutting them up: https://www.techpowerup.com/forums/t...-noise.294015/

[Diah]

Re: Samsung UN46F6800 LED TV Buzzing and Vibrating on Startup

take out the board.. and inspect soldering joint point at the backside.

[nomoresonys]

Re: Samsung UN46F6800 LED TV Buzzing and Vibrating on Startup

Yep, good idea Diah, forgot to mention that.

[lotas]

Re: Samsung UN46F6800 LED TV Buzzing and Vibrating on Startup

If there was bad soldering on the other hand, then the contact would disappear on these chokes through which the alternating voltage passes and the TV would constantly turn on and off, then the coils would rather peel off from the core and when the alternating current passes, a magnetic field is created and the coils vibrate on the core, Pour a lot of these places with hot glue or sealant.