Floor lock don't work every time

check the wiring on your leg microswitches

check the wiring on your leg microswitches

Does the hand control show "locked" even though the feet aren't extended? Microswitches/Wiring

If the feet are extending fully but the table still moves, they need to be adjusted, or replaced if the rubber pad is missing. I use a regular Sharpie as a feeler gauge to set my feet. With the locks fully retracted adjust the foot so the Sharpie just slides between floor and foot. 

Clip your DVM on the foot microswitches and watch the voltage as you try to duplicate the intermittent problem. Those switches get dirty with grime and oil so they frequently have dead spots.  I am assuming you already eliminated the remote control because the remotes have a history of intermittent problems, especially the brake unlock/lock.

Did you get this resolved?  I have a table doing the exact same thing, sometimes.  This happening on all the controls, like i can raise the feet up but when i try to lower it, it will only go for a half second then stop like my thumb slipped off the button.  I'm going to check the battery voltage next as advised from a steris tech.

The microswitchs on the feet that detect if the is foot is up or down have levers which move with the foot.  As the lever moves, the switch contact moves.  You need to verify the switch remains open or closes during the whole movement. Dirt and dead spots in the switch may cause the switch to change from open to close or visa versa. Clean the switchs and ohm them out while slowly moving the lever and make sure the switch stays open or closed as it should.

I can see now where I was unclear.  It's happening on every other  adjustment of the table, not just the floor locks. and it comes and goes.  Also not the controller.

Failing pump, failing solenoids, voltage regulatory, power supply, bad hand control?