A few things which cause grounding problems:
1. Grounding cheater plugs. (Those handy little 3 to 2 prong electrical outlet adapters) Used on equipment connected to the cable system , this will almost guarantee the appliance will use the cable as a ground.
2. Improperly wired outlets. (i.e.: Hot-Neutral wires reversed) Will cause hot chassis (current on ground) condition on A/V and computer equipment.
3. Polarized plugs, inserted backwards. These plugs are designed to be plugged in one-way for a reason, don't force them or modify them to fit in backwards.
4. Replacing 2-prong outlets with 3-prong outlets and not connecting a ground wire. Occurs mostly in older homes with handyman electricians around, causes a false sense of security and a very dangerous electrical problem.
5. Disconnecting or not having the coax cable ground. Illegal situation per the National Electric Code. Severe damage can occur to both cable company equipment and customer equipment if electrical surges occur. (Lightening, electrical line crossing cable lines, dropping a TV in a bathtub, etc...) Coax cable systems are grounded to prevent excess current from the customers home reaching the cable plant and to prevent excess current from the cable plant reaching the customer's home.
There shouldn't be more than 1 volt measurable between the coax cable and a known good ground.
How to check for grounding problems:
1. Check for the problems listed above. 90% of the time the reasons listed above are the causes for excess voltage on the coax cable system.
2. Use a electrical outlet tester.
3. Use a volt-meter or multi-meter, if you have proper instruction.
How to fix grounding problems:
1. Call you cable company to verify your house coax cable system is properly grounded. This should be done at no cost as it is required by law.
2. Call a certified electrician to verify proper grounding of your home electrical wiring and repair any problems found.
3. Remove any offending electrical equipment which is causing grounding problems.
Grounding problems, at their least, will cause intermittent or no connection on cable modems and poor or no picture on televisions. At their worst, grounding problems can lead to destruction of property and loss of life.
See the following link for interesting information on grounding issues and the problems they cause:
»www.epanorama.net/documents/grou ··· undloop/
Thanks to MacLeech for this submission.
Note by habu187 : Improper grounding can also cause "humbars" in pix.
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