PLC / RF Transmitters, Receivers and Transceivers (http://www.x10community.com/forums/index.php?topic=9899.msg57801#msg57801)
I have a KR19A KeyChain Remote, a TM751 Wireless Transceiver Module, and a SR227 wall receptacle...
Any other PLC transmitters?
CM11A or CM15A? ELK ESM1?
Lamp or appliance module?
...the remote on/off buttons successfully control the receptacle on the bottom of the transceiver, but has no effect on the controlled outlet of the wall receptacle...
...The remote has a brand new battery...
Which validates the remote and the RF section of the TM751 - it sounds like the PLC Transmitter of your TM751 is dead, but to be conclusive, you either need more equipment to run more tests or to replace it (with a RR501 if you plan on having more than one).
TTA's "Quick N Dirty" X-10 Troubleshooting Hints... (http://www.x10community.com/forums/index.php?topic=9899.msg57815#msg57815)