Some of you know we have an Ocelot for our home automation controller. That with the XTB-523 working as its powerline interface had provided virtual 100% reliability since we moved into this house. But over the last several months reliability had deteriorated. While still above 99%, occasionally the hall light controlled by an extended code was not at the proper brightness for that time of day. Then over the last week it seemed like ghosts invaded the house, with lights switching on and off randomly.
Since years ago the power module had failed, I swapped in a new module. But then the Ocelot would no longer communicate with the PC. Hmmm...
I swapped in the backup I picked up on eBay. It would not communicate with the PC either. So thinking I had somehow damaged the serial port, I tried a different port. Still no go... Then I noticed the case on the Ocelot seemed warmer than usual.
I pulled the cover, and the electrolytic capacitor was hot. Monitoring the rectified voltage with a scope showed the capacitor was not filtering the rectified voltage at all. Checking the original Ocelot showed it had a similar problem with a dead electrolytic. I replaced both electrolytics, and both Ocelots are again working as they should.
So, if you have an Ocelot that begins to misbehave, check the electrolytic in the upper corner. If warm at all, it should be replaced.
Jeff