X10 is typically used in more mundane applications ... like turning your lights ON at Dusk and OFF at Dawn - i.e. twice a day. So having to go ON/OFF thousands of times (Check out this 200x time-lapse of an XTBM Signal Meter) a night is a severe test of X10 equipment and certainly way beyond their design criteria ... and I typically have a couple of SR227 X10 Super Sockets "die" on me every year. Instead of a "click" for ON (or OFF), they stay in the ON position and when commanded to go OFF, you hear a "machine-gun" click-click-click - here's an audio that describes what happens.
As seen in the pictures below, I have collected quite a few "bad" X10 Super Sockets and Modules. So when the first one died in 2012 (and I was down to my last backup), rather than buy more on eBay, I did some Internet research and came across these two great writeups here and here.
In a nutshell, the most common failure mechanism is breakage of a thin plastic tab that then prevents the solenoid mechanism from working. Another problem is the points get pitted from internal arcing. Both of these manifest themselves as a "click-click-click" as the Super Socket fires the Solenoid several times to try to get the unit to work.
Most of my SR227's had broken plastic tabs - and I didn't even try repairing that as even Epoxy probably wouldn't work. But it was intact on several others and the problem was pitted points, so it was a fairly straightforward to disassemble the Super Socket (two sets of two screws), clean up the points, and then put it back together ... and I was able to get three of them back into working condition. Some pictures below illustrate the process.