philips 50Mf231d/37 plasma distorted buzzing sound from speakers

[shelby5041]

hi i got this tv the other day

powers on fine and video is fine but it seems to have a slight humming distorted sound coming from speaker...its not a constant loudness seems to flucuate a bit....

if i mute the tv the buzzing still continues coming out of the speaker...but goes away after about 10 seconds

if i unmute the buzzing sound comes back...and stays buzzing as long as sound is not muted

the buzzing does go louder if volume is increased.

i do see 2 bulging caps on power supply board ...just an observation

the buzzing is not coming from the caps.....its in the speakers

any help would be appreciated

[dick_barton]

Re: philips 50Mf231d/37 plasma distorted buzzing sound from speakers

Change the caps first since it may be allowing poorly filtered DC to the audio amplifier/preamplifier.

[shelby5041]

Re: philips 50Mf231d/37 plasma distorted buzzing sound from speakers

some more observations

the pitch of the buzzing sound seems to change a bit depending on whats being displayed on the tv....

the volume level does not affect the buzzing...even if you have volume turned all the way down but not actually muted the sound is still there....

as soon as you mute the sound..the buzzing goes away after 10 seconds

[shelby5041]

Re: philips 50Mf231d/37 plasma distorted buzzing sound from speakers

yes i was kind of thinking that...i will change them

they appear to be a pain to get to..may have to remove some other componenets but will try it.....

[shelby5041]

Re: philips 50Mf231d/37 plasma distorted buzzing sound from speakers

more observations

if i have tv on with nothing connected to inputs here is what happens when i cycle through these inputs and it doesnt matter what level the volume is on.

av1...buzzing coming out of speaker...does not go away
av2..buzzing coming out of speaker..does not go away
av3.buzzing coming out of speaker..does not go away
tv..buzzing coming out of speaker but goes away after 10 seconds
hdmi..buzzing coming out of speaker but goes away after 10 seconds
side av..buzzing coming out of speaker ..does not go away

if i hit mute button the buzzing goes away no matter what input im on

[shelby5041]

Re: philips 50Mf231d/37 plasma distorted buzzing sound from speakers

disregard post #5

i just hooked up a tv signal using antenna and when channel came in the buzzing is there and does not go away same with hdmi when video is played and sound not muted

anyways i will replace the caps...just making some initial observations on this unusual issue

[shelby5041]

Re: philips 50Mf231d/37 plasma distorted buzzing sound from speakers

Hey burton....thanks for advice..it appears the buzzing from speakers is gone onve inreplaced the 4 bad 470uf 35v caps

They were a pain to get to...under heatvsink overhang....indidnt wantbto remove 50 components so i surgically removed them.....difficult tight space but i did it.....using some odd techniques

Solder wick wouldnt work on the leaded double sided board so i had to deal with that

[shelby5041]

Re: philips 50Mf231d/37 plasma distorted buzzing sound from speakers

Will test a while and see how it goes...but initially the buzzing from speaker is not present like it was prior to changing caps......could be a good catch by you.......i only paid $10 for the tv couple days ago....it has a great picture