Question: Voltage From Cable to Receiver.......

#1
Could someone who has a clue, please fill me in......
I just had DTV installed. After 1 day the guide stopped updating and I started receiving the informational windows on the screen "your guide has not updated for 1hr" then it went to 3 and 7 and so on. I eventually turned the power off and restarted the receiver. That temporarily fixed it. After an hour, it was back. I called DTV and was instructed to do a hard reset instead of a soft reset instead. I unplugged the receiver and as I grabbed the cable to unscrew it from the back. I got zapped! I did have the HDMI cable (still plugged into the tv) in the other hand. The DTV Tech came out and felt the shock. He stayed and checked all the equipment. We tried every wiring combination possible to stop it but nothing worked. He then instructed me it was my brand new tv. However, they did replace the receiver.
Today, I had my electrician out for other reasons, I asked him to test the end of the cable coming in from the dish.... 5 volts and the HDMI. There is a just below 1 volt coming out of the HDMI cable. When those 2 draw on one another and "amplify", we are looking at 10 volts....hence my ZAP! I would like to know if the voltage coming out of the cable is normal and if so, where does that go? I am not interested in that burning up something in my TV or other devices.
 

FOX TV

Contributor
#2
Could someone who has a clue, please fill me in......
I just had DTV installed. After 1 day the guide stopped updating and I started receiving the informational windows on the screen "your guide has not updated for 1hr" then it went to 3 and 7 and so on. I eventually turned the power off and restarted the receiver. That temporarily fixed it. After an hour, it was back. I called DTV and was instructed to do a hard reset instead of a soft reset instead. I unplugged the receiver and as I grabbed the cable to unscrew it from the back. I got zapped! I did have the HDMI cable (still plugged into the tv) in the other hand. The DTV Tech came out and felt the shock. He stayed and checked all the equipment. We tried every wiring combination possible to stop it but nothing worked. He then instructed me it was my brand new tv. However, they did replace the receiver.
Today, I had my electrician out for other reasons, I asked him to test the end of the cable coming in from the dish.... 5 volts and the HDMI. There is a just below 1 volt coming out of the HDMI cable. When those 2 draw on one another and "amplify", we are looking at 10 volts....hence my ZAP! I would like to know if the voltage coming out of the cable is normal and if so, where does that go? I am not interested in that burning up something in my TV or other devices.
Are you sure this is not a static electricity situation? That's what it sounds like to me, as 10 volts of DC or AC would not really be enough to cause a ZAP as you describe it, especially if it actually jumped an arc out to you. I assume you are talking about Dish or Direc TV when you mention "I just had DTV installed ".

Do you have a mufti room dish installation, or a single receiver installation? In single receiver installations, the coaxial cable actually carries the voltage that powers the electronics on the dish, and that voltage cannot be easily measured with the cable connected to the receiver.The one volt measurement on the HDMI cable could be the video voltage level , as it normally never exceeds one volt, especially in analog video.

Static discharge is a big problem in the dry air of winter, and the voltage levels in a static discharge can be as high as 40,000 volts and digital electronics can be damaged by these discharges.
 
#3
Sounds like your dish/home isn't grounded properly.

There should be NO voltage coming from the dish. Static could explain one jolt but it won't explain a measured 5 volts (once discharged it would read 0).

I would say to check your outlet wiring for hot/neutral reverse, but as you describe the problem (reading 5 volts coming from the dish with receiver unplugged) it is certainly related to improper or lack of good grounding.

Here's some information about what the dish should look like when it is properly grounded.

Grounding
 
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