Home>Discussions>ELECTRICAL & LIGHTING>Help with tv/ internet cable sparking
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Atlanta Kwood
Help with tv/ internet cable sparking

I just upgraded my tv to an hdtv. I already had a hd/dvd cable box connected to my tube tv so just needed to change the tv out. When I went to connect the hdmi cable from the box to the tv, it sparked (big) and melted the tv connector and that end of the cable. What could have caused this? When it happened, I remembered something similar happened a while back when I tried to replace the cable leading from the internet outlet at the wall - it also sparked, but not nearly as bad. Any insight?

canuk
Re: Help with tv/ internet cable sparking

Hard to say ... the HDMI is a low level digital signal with likely no more than 12 volts DC.

WitchDoctor
Re: Help with tv/ internet cable sparking

Is it a shielded wire ? If so , it may be a path for current , suggesting a bad neutral connection somewhere . Just a wild guess .

tgossman
Re: Help with tv/ internet cable sparking

I work for one of our local cable companies and while I haven't seen this happen with a HDMI cable, I have seen it when connecting lines at a splitter. This can be caused by a faulty ground, either with your home, or with the cable system where it comes into your home. It's also possible to have a device in your home that back feeds voltage into the cable wiring inside your home. My advice would be to contact your cable provider and have them take a look, as well as contacting your electrical provider and ask them to inspect your house ground (usually a free service) make sure you contact them and not an electrician as they will charge you for a service call and the power company USUALLY will not.
Hope this helps!

Tgossman

xyxoxy
Re: Help with tv/ internet cable sparking

This question just made me think of a question of my own.

I don't have a lot of experience running coax cable but I'm installing an attic antenna and running coax via a splitter to several rooms in the house.

This is in no way connected to cable TV or satellite. It will simply be an over the air HD signal, probably with an electronic signal booster.

In this instance does the coax still need to be grounded? And if so is there any issue with tying into an electrical ground already in use in the attic? There are no pipes handy to ground to so it's either that or run a dedicated ground wire all the way down.

canuk
Re: Help with tv/ internet cable sparking

An outdoor antenna it's mandatory to have the antenna and coax grounded to either it's own ground rod or where the electrical service is grounded.

Being that your antenna is mounted indoors in the attic there isn't a requirement for providing a dedicated "ground".

In your case if the set up would be a passive arrangement the coax would simply be the transmission line carrying the RF signals from the antenna to the TV. The braided shielding inside the coax cable is used to "drain" spurious interference. The braid is in contact with the metal F connector on the cable and when attached to the receiver is tied to "ground" through the receiver internally.... allowing the interference to drain to ground.

In my opinion if you were to tie the coax to a ground from another electrical circuit in the attic you are tying 2 separate circuits together and could create a ground loop.

Let's say you have a surge protected power bar plugged into the upstairs circuit.

The way surge protectors generally work is when a "surge" was to occur the MOV's used in the power bar route that surge to ground.

So in theory ..... that surge could be directed through the coax cable from that ground and be routed to the receiver at the other end and could damage it.

Btw ... here is a link you might find useful : http://www.hdtvprimer.com/ANTENNAS/basics.html

Just 2 cents. :)

JLMCDANIEL
Re: Help with tv/ internet cable sparking

I have not seen any TV's that were grounded. They all have 2 prong plugs. Aground wire can be added anywhere, at the antenna or at the splitter and can be run to any ground including an electrical ground if the antenna is inside.
Jack

canuk
Re: Help with tv/ internet cable sparking
JLMCDANIEL wrote:

I have not seen any TV's that were grounded. They all have 2 prong plugs.

Yep.... the way it was posted was misleading ... I didn't mean to imply the TV is tied into the electrical circuit ground via a third prong on the cord .... rather the the tuner's shielding tied into the internal circuit's ground.:o

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