ECN Forum Forums General Topics of the Trade Voice - Data - Video Discussion VGA ground loop isolation?

Is this on a cable TV system?
The hum may actually be coming down the cable. Try disconnecting that. That could be the only ground reference on a TV that has a 2 prong plug.

Would converting the analog VGA and audio signal to a digital HDMI signal help clean up or eliminate the noise interference in both the audio and picture?

NJwirenut,

Any updates?

didja fix it?

LarryC

Eventually got things fixed. The CATV grounding was good, tied into the electrical grounding system where it enters the house.

The solution involved 3 separate fixes, each of which improved the hum somewhat, but all 3 together were needed to eliminate it completely.

First, the audio ground loop isolator I had ordered was installed in the audio line, and this eliminated the buzz from the audio.

Installing a similar device in the coaxial RF input to the cable box (which connects to the TV via 5 RCA cables for audio and component video) greatly reduced the severity of the hum bars, but didn't completely eliminate them. The device I used is here:

http://www.amazon.com/VSIS-EU-Cable-Ground-Loop-Isolator/dp/B0017I3K9M

Eliminating the last traces of the hum bar was accomplished by running a 10 AWG THHN grounding wire between the PC chassis and the chassis of the TV. Getting a connection to the TV chassis required removing the back cover of the TV, and attaching the wire to an internal metal shield.

Thanks to all for the input!

What happens now if you remove the filters?

best solution is dedicated circuit and or Isolated ground

micro devices such as dimmers and occupancy sensors placed on switch loop circuits use the ground for a neutral when none is available and this puts small current on ground connection.

Also and perhaps I should have led with this is there a woofer nearby these cause havoc when nearby