Installers and integrators routinely test continuity on most wire connections to their AV component installations. However, some times stubborn problems with IR codes and RF signals can defeat the usual testing tools and methodology.
With a few extra 3 and 6 pin Phoenix connectors, an IR Emitter and Receiver, it is possible to create some tools for testing the wire path to and from your AV components and the D5K. In many cases it is an important step to eliminate these as a source of problems by insuring the signal is arriving where you want it to, and in the form you intend.
Here are just a few cases where wiring and RF or IR signal strength can be the source of problems:
Weak signal from IR receiver at AV component to D5K
Misplaced IR emitter at AV component (not directing signal to IR receiver in component)
Broken or bad connection in IR emitter wiring from D5K to AV component
RF Antenna on D5K blocked by metal objects, chassis or other RF interference
RF signal from remotes blocked by metal walls, fireplace boxes, elevators, etc.
Loose wires on Phoenix connectors (misplaced wire in screw block)
A simple method of checking either the signal strength or receipt of IR codes at the AV component, is to connect an IR receiver near the D5K. Xantech makes a number of receivers that work nicely for this; Dinkylink or Hiddenlink are examples. They are small, require a standard 12v power adaptor, and are easy to improvise.
If the IR path is not working connect an IR receiver to one of the IR input ports on the Domain Controller. Unscrew the appropriate IR emitter from the Phoenix connector it is connected to. Connect it to the same port as the IR receiver. Test by sending IR commands to the receiver.
Then using the AV components handheld remote, a Destiny Remote or Pronto; send some IR codes through the receiver, up the wires to the component wherever it is in the house and watch the results. Obviously, a successful test will cause the component to react to the IR codes you are sending.
If there is no reaction, there may be a problem with either the wiring OR with the IR codes, depending on which remote device you are using to test with. If you are certain that the IR codes are good, then you most likely have a wiring disconnect somewhere along the way. If all tests are successful, you have eliminated your wire path as a source for any problem.
Another useful test is to create a 'port tester' using a small low voltage LED which can be found at Radio Shack or other electronics vendor.