DVI to HDMI lound Buzzing noise - AVS Forum
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post #1 of 5 Old 09-19-2013, 07:22 AM - Thread Starter
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Hi, I've got a very lound buzzing noise coming from my TV when connecting my PC to the TV using the DVI to HDMI cable, Here is the detailed setup:
PC: HP DC7900 mini tower running windows 7. there is not spdif output on the motherboard.
Video Card: MSI 250GTS with 2 DVI-I dual link output, and the card is in the PCI-E X4 slot (X16 won't fit because of the chasis fan). The card has spdif input.
TV: x37sv-komodo - Sceptre
When the system started and get into winodws, there is a loud buzzing noise coming from the TV speakers even thoug I turn the volumn all the way down to mute. I am using the DVI to HDMI cable comes from the TV.
And here is the interesting poing: when the PC turns on, the TV has to be set at DVI so I can see the initial loading process (BIOS etc). But when the "start windows" stared, and a few seconds later, the screen goes blank. I have to set the TV to HDMI so I can see the screens, and this is when the loud buzzing noise starts.

And on a side note, anyone have this TV hooked up to a PC have a hard time to adjust the screen? although the manual says for PC, 1360*768@60Hz (native), I can't make it work. I have to use the nvidia's tool to adjust the screen and the final resolution is a weard 12xxX7XX.
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post #2 of 5 Old 09-19-2013, 09:05 AM
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Originally Posted by lan_baba View Post

there is a loud buzzing noise coming from the TV speakers even thoug I turn the volumn all the way down to mute. I am using the DVI to HDMI cable comes from the TV.

This just screams 'ground loop'. If that's true, it means there is a small voltage difference between the grounding points for two pieces of equipment. That is driving a small current across the HDMI cable, and the TV speakers are reproducing it as a 60Hz hum or buzz.

Are the PC and TV connected to different wall outlets? Is there a UPS involved? Is there a coax cable also connected to the TV? What happens if you disconnect all inputs to the TV except for the PC. What happens if you connect the TV and PC to the same power strip?


http://www.audioholics.com/home-theater-connection/ground-loops-eliminating-system-hum-and-buzz
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post #3 of 5 Old 09-19-2013, 09:14 AM - Thread Starter
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The TV is on the UPS. maybe that is the reason? There is no other devices connected to the TV. I used a HDMI switch to connect multiple HDMI devices to the TV. But with or without the switch, the noise exists.
I will try to connect the TV and PC to the same strip and test it.
Will the ground loop make such a big noise? It is really loud, can be heard from the other side of the house, not a low humming sound.

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Originally Posted by EricN View Post

This just screams 'ground loop'. If that's true, it means there is a small voltage difference between the grounding points for two pieces of equipment. That is driving a small current across the HDMI cable, and the TV speakers are reproducing it as a 60Hz hum or buzz.

Are the PC and TV connected to different wall outlets? Is there a UPS involved? Is there a coax cable also connected to the TV? What happens if you disconnect all inputs to the TV except for the PC. What happens if you connect the TV and PC to the same power strip?
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post #4 of 5 Old 09-19-2013, 09:34 AM
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Quote:
Originally Posted by lan_baba View Post

The TV is on the UPS. maybe that is the reason? There is no other devices connected to the TV. I used a HDMI switch to connect multiple HDMI devices to the TV. But with or without the switch, the noise exists.
I will try to connect the TV and PC to the same strip and test it.
Will the ground loop make such a big noise? It is really loud, can be heard from the other side of the house, not a low humming sound.

Definitely test with and without the UPS. The fact that you hear the buzz with the TV speakers muted strongly indicates mains hum. Usually it's not 'hear it across the house' loud, but with a UPS involved, all bets are off.
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post #5 of 5 Old 09-19-2013, 04:54 PM - Thread Starter
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I disconnected the UPS and now the TV and PC on the same strip. If I put the mute on, there is no noise at all; but if I turn the volume all the way down to zero, the noise still there. it now sounds not so sharp (like cracking sound), but still lond and humming.
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