Let's forget about the door, its springs and torque adjustments. This
is an RF problem! Neither a new remote nor the original remotes will
actuate either the new receiver or the old receiver. Has nothing to
do with the door itself or the closer. There is something near that
physical location that prevents the receivers from getting a valid
signal from the remotes. I am looking for ideas as to what that might
be. This is an all-house neighborhood. No businesses of any kind.
Nearest thing other than houses is a high school two blocks away.
Power lines are overhead, not buried.

I think you're going to have to find something that's capable of
acting as a spectrum analyzer (or at least a crudely-tuned RF
sensor/signal-strength-meter) and start DF'ing.

A ham HT with 70 cm capability, and a 'scan' feature, might be enough
to find the signal frequency fairly quickly if it's strong enough to
interfere with Part 15 devices. Then, start hunting. A simple
hold-it-near-the-chest-and-spin-on-your-heels 'body fade' might be
enough to allow you to triangulate in on the source.

A two- or three-element Yagi hooked to a real spectrum analyzer would
probably be rather faster.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
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