Bell System Practices 630 Series Installation And Maintenance Manual page 16

I
SECTION 502-600-100
Fig. 25—Key Frame Raised in Current Production
Telephone Set
(3) If malfunction is related to one key module
test key for proper operation.
3. I I To prevent release button from binding on
headset equipped early production telephone
sets install a 811256726 (1'-l2E672) collar as follows.
(1) Remove faceplate assembly.
(2) Remove two switch assembly screws (Fig.
31).
(3) Remove button assembly.
(4) Place 811256726 (P-12 E672) collar around
811159284 (P-11 E928) plunger (Fig. 31).
(5) Reassemble switch assembly.
3.12
Improper operation of 667-type transmitters
may be caused by interference between the
printed circuit board and terminal screw of TBW
—
Fig. 26—Key Frame Raised
on Early Production Telephone Set
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