Question:  I need to remove the cover on the EF-701M in order to access the internal jumpers.  I removed the case screws but the cover will not come off, it appears to be held in place by the XLR connector which is riveted in place.  How do I remove the cover without drilling out the XLR rivets?
Answer: 
Three tools are required for this procedure: a #2 Phillips screwdriver, a 3/16 in. nut driver,
and a flat-bladed screwdriver with a blade width of approximately .075 in. (1.9 mm).
To remove the cover of the EF-701M unit:
1. Disconnect all cables.
2.Remove the four sheet metal screws on the back and sides.
3.The XLR jack has a special locking tab to secure it to the housing. The jack must be released before the cover can be removed. Use a very narrow-tipped screwdriver. Insert it into the slot inside the XLR jack and twist the release lock counterclockwise for approximately 1/4 turn.
4.Remove the two 3/16 in. hex-head jack screws on the DB-15.
5.Slide the cover backwards until the DB-15 and XLR jacks are clear.
6.Lift off the cover.
7.Make the necessary adjustments of jumpers P3 and P4 (shown in the following table).To set a jumper to the closed position, plug it onto both pins. To set a jumper to the open position, plug it onto only one of the pins.






8.For reassembly, reverse steps 1 through 6.
Note: The potentiometer (R13) is used to factory tune the 20-kHz call-signal detection circuitry. It should be adjusted only by qualified personnel.