Eversafe PHT 1 DIMMER - Electrical Supplies

If it is new and isn't working, take or send it back to get one that does work.

Depends on what kind of connection you are using,

Try unplugging power cord from all equipment, also unplug audio and video cables, wait ten or fifteen minutes, cable everything back together and restart.

Let me also know what cables you are using to connect the TV.

The green will be the ground wire. Your Hot wire will connect to one black wire on the dimmer. Your Switch leg will connect to the other black wire on the dimmer.

There are no repair parts for in-wall electrical devices.
When they go dad you buy another.
Lowes and Home Depot carry inexpensive dimmers.
Look for 3 things:
1) Wattage: most off-the-shelf dimmers are 500-1000Watts. Add up total wattage.
2) If you are dimming incandescent bulbs, dimmer package will say tungsten or incandescent.
Package will say florescent if dimmer also works for florescent bulbs.
3) If dimmer is 3-way, with a dimmer on either end of a room, many times the dimmers are sold as a package of 2 dimmers with 1 dimmer that controls the other dimmer.

Lutron dimmers
http://www.lutron.com/Products/StandAloneControls/Dimmers-Switches/Pages/DimmersSwitches.aspx
Leviton dimmers
http://www.leviton.com/OA_HTML/ibeCCtpSctDspRte.jsp?section=15265&minisite=10025

The important thing to remember is your switch has two wires.
Sometimes the colors vary a bit because of the specific circuit.
The green wire, when present, is a ground wire, and always connects to bare copper wire.

If your dimmer has two black wires, then connect dimmer-wires to either switch-wire
If the dimmer does not work, simply reverse the two wires.

If your dimmer has a red and black wire, then connect dimmer-black to switch-black, and dimmer-red to switch-white.
Again, if dimmer does not work, reverse the two wires.

Answer back if you have trouble, and I will help.

If this is a new dimmer, please check the wiring.
If you are having a problem with wiring, re-post your question with exact model number

If your dimmer is old, the electronics inside dimmer have probably gone bad

When buying a new dimmer, watch for two things
1) is dimmer rated for enough wattage?
2) Is dimmer 2-way or 3-way

you will want to make the following connections
existing-black wall to black dimmer now connects to red dimmer
existing black wall to red dimmer now connects to black dimmer
existing red wall to black dimmer now connects to red dimmer
Green wire connects to bare copper wires in wall

no a single pole dimmer is for 1 location control you need a 2 location control dimmer, return the dimmer for an exchange ensuring you tell them 2 location master dimmer

sometimes the reader is dirty and need to be cleanead you can sometimes do this by spraying compressed air from a can through the slot or you may have to open unit to access

The answer to your question depends on the manufacturer and type of 3 way dimmer you are using... generally you can use a 3 way switch as a single pole switch, but whether or not this holds true with the dimmer you are using depends. Let me know what you are trying to acomplish and model numbers mfgs of what you have and I'll try and help