Help with troubleshooting a Zone VI Compensating Development Timer

I last used the timer about 6 weeks ago and it performed perfectly. I started a printing session last night and turn on the timer and the display came on as usual but when I tapped the footswitch - nothing, the timer would not start.
Here is what I have tried:
*Turned on and off - no help/
*Unplugged and reinstalled the sensor, footswitch and power supply cables - no help/
*tested continuity of the footswitch - when footswitch is depressed there is continuity.
*it is plugged into a receptacle that is switched so when not in use it is not connected to power.
*I have not opened it up yet.

Anyone with any experience or suggestions would be appreciated.

Thanks in advance

Todd

Somewhat recently, my footswitch started acting weird, too; depressing it wouldn't start the timer or it would toss up some random time value. I noticed about a year ago, that it wasn't keeping time properly (something ya kinda want in a timer!) I was very careful how I tested this anomaly. Anyway, long story short I contacted Paul Horowitz and he does warranty repair on these units at no cost (other than shipping, of course.) At the time, he was away for several months but said he'd be back early May. I plan to send my unit to him for repair / recalibration. If you're interested in having him look at it, PM me and I'll pass along his email address.

@Alan9940 Thanks!

Maybe try cleaning the switch plug? If you short the switch socket with a wire does it start?