Home Forums General Discussion Technical Questions Dover DMC-1 issues

To anyone who has had this problem. While changing the small watch type battery in the car station on the clc board with the power on. Once the battery was changed the elevator would not respond to any type of calls or run on top of car inspection. When the elevator is sitting on automatic at floor level I have all the relays energized except "in" and the question is how do I get "in" to energize and what does "in" stand for? The prints on this site do not seem to match the unit which makes it even more difficult. Do I need the "programming tool" in order to correct this problem or is there something that I am completely missing? Any suggestions would be greatly appreciated.

are you sure you didn't short out the little clip that holds the battery in to the other side , when the battery was out thus frying the clc board.

Thanks for your response

Oh man! Servicing those CLC boards with the power on is bad news bears! We had a mechanic try to service the stop sw with the power on and shorted the CLC board. It was a mess.

We change CLC batteries with power on all the time. While it works on most, occasionally you do need to reprogram a unit. Sounds like you have one of those units. We change the batteries annually on DMC units and I normally send one guy around to do all of them. While he ends up with allot of wheel time, it ends up faster than having the individual mechanics play around with resetting the units. Whenever we get a new one on service, we go out and copy the software chips and back up the programs. That way we have all the settings in case of a failure.

Ya same. Saves time in the future because you will have to reprogram it at some point.

If you happen to be servicing one of these units and your not sure if the battery will hold the memory while powering down, here is a tip. Open cop to gain access to the CLC board, then measure the DC voltage at the D4 diode. The voltage on the anode side is the battery voltage, the cathode side is the 5 volt power supply voltage. There is a ground connection on the CLC board for your common. Don't turn off power if D4 anode voltage is less than 2.5 volts. A fully charged new battery should read near 3 volts. Some times mechanics will measure voltage right at the top of the battery, this will tell you battery voltage, but if the clip is loose or corroded the voltage won't make it to the diode to hold memory. The D4 diode is just above the battery a little to the left if memory serves me. If the diode is missing or cut out you will lose memory on power down, I have had this diode missing on everyone of the cars at a new job we took over, seems the mechanic that had the job previously thought this was a good way to cause trouble for the next guy. Remember you are only screwing your elevator brothers when you sabotage a controller.