mikeusa,
Welcome to the forum.
From your description, I'm assuming that your Motion Detector/Flood Lamp is correctly sensing motion and turning your outdoor lamps on. It isn't communicating (X10) with your indoor chime - Correct?
I've had the PR511 version installed for ~8 years now with no problems (3 units). I'm not sure what vintage your unit is. With this in mind, I'd lean toward a new device (noise source or signal absorber) installed in your home that is now preventing communication.
I'm also assuming that you don't have a X10 computer interface (CM15a or Cm11a) that can monitor X10 transmissions. If that's the case, you'll need to revert to some "old fashioned" troubleshooting techniques.
Assuming that you motion sensor is sending a signal, and your chime can't "hear" it, try the following -
- Search for newly installed devices (computer, TV, ETC) and unplug.
- Move your chime module to the same circuit as the flood lamp. If this isn't possible, try a branch circuit close to your load panel and on the same phase.
- Breaker method - Install your chime module on the same phase as the flood lamp and turn off all the other breakers in your load panel.
I have had my PR511's get confused as a result of a power interruption (they interpret this as a ON command). Although this doesn't sound like the problem you are experiencing, you could try removing power from the unit for a few minutes.
Get back with us with your results. It is possible that your floodlamp has succommed to corrosion. That would entail a completely different troubleshooting path. If you're interested, there are schematics located here :
IdoBartana PR511 SchematicBoiler