I have a CicloMaster CM414 and a CM434 computer on my two road bikes.
As far as I can tell, these are the same computer, except for the shape
of the cases, and the mounting "hardware" (the newer one uses a big
rubber band!).
About two weeks ago, I noticed that the CM434 wasn't registering any
speed or distance, although the altitude and time of day were available.
I figured that meant the battery (A23) in the transmitter ("sensor" in
the printed instructions) must be dead, so I changed it. That made no
difference. So then, I changed the battery (CR2032) in the receiver
("handlebar bracket" in the literature). Still not working. Then I
started messing with the magnet. Once I loosened it, I could not get it
to clamp onto the bladed spoke anymore. The LBS was nice enough to
supply me with a new magnet, but didn't have time to troubleshoot my
problem.
Two days ago, I started a ride on the other bike, and the CM414 wasn't
showing any speed or distance. The same attempts at fixing the problem
have yielded the same result - nothing.
It has been cold for Southern California lately, with morning
temperatures around 40F (5C), but one day as low as 37F (3C). The days
I observed failure were not quite that cold. The bikes are stored in my
garage, where the temp rarely falls below 60F (15C).
I am not positive that the Energizer A23 batteries I used as
replacements are fresh, but they were in a sealed package when I found
them in the "battery box" at home. The package says Copyright 2004, but
has no other date on it.
On the bike with the CM434, I am actually using a sending unit from a
Trek computer, since the markings were the same on the unit, and the
unit was already mounted and working. It worked for about 20 months.
So I have a spare sending unit in the CicloMaster box. On the other
bike, the CM414 sending unit has worked for roughly 5 years (I seem to
have replaced the battery at least once).
Does anyone know what else I can try to get the computers functioning again?