I got my ESE ES-911 to work.    The problem that I was seeing was that the unit 
was not seeing data from the GPS receiver... it would not show a GPS lock, even 
though the GPS receiver (a Motorola M12+) was working properly.    Probing 
around the ESE motherboard showed the GPS receiver was not sending any data.    
I assumed (improperly) that the GPS receiver was not being initialized to send 
data by one of the two microprocessors on the ESE motherboard (no data seen 
being sent to the GPS receiver).

There are two batteries in the ES-911.  One is a 6V 1.2Ah gel cell.   The other 
is a tiny ML-621 rechargeable lithium coin cell on the back of the GPS board.   
Both batteries were dead.   It turns out that the microprocessors do NOT 
initialize the GPS receiver!   You have to do that over the "auxiliary" data 
port (the DB-25 connector).  Pin 2 is the "config" pin.  It is a RS-232 level 
serial input connected to the GPS receiver RXD input pin.  There is no external 
connection to the GPS TXD signal so you cannot monitor the GPS receiver.

To initialize the GPS receiver, I built a two wire adapter cable to connect a 
PC serial port to the ESE "aux" connector (PC pin 3 (TXD) to ESE pin 2,  ESE 
pin 7 (ground) to PC pin 5.  I then used Lady Heather configured to talk to 
Motorola receivers (heather /rxm /serial_port#)  This sends commands to 
initialize the Motorola receiver on the ES-911 motherboard.  Voila... ESE-911 
started working properly.  Note that Heather will complain about not seeing any 
data from the receiver since the ES-911 does not have any way to send the GPS 
serial data to the outside world.

While connected to the "config" port you can use the "PC" keyboard command to 
set the antenna cable delay.  Note that this will be a "blind" command with no 
apparent response back to the computer.

After initializing the GPS receiver I moved the PC serial port cable to the 
ES-911 "broadcast" connector and re-started Heather.  Heather v6.30 and later 
can decode the ES-911 time codes sent out the "broadcast" port.

So if your ESE ES-911 loses input power,  6V backup battery power, and the GPS 
coin cell drains then you will need to fix the battery problems and then 
manually re-initialize the GPS receiver in order to get the device working 
again!
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