the cover. Lift the transmission network off the
relief bushing in the cord hole, and connect the
threaded studs. Position the new transmission network
terminal wires to the terminal board.
on the studs and secure it to the cover. Connect the 17
Dial.-- To replace a dial, remove the telephone set
lead terminals to the network. Reconnect the terminal
from its enclosure and disconnect the terminal wires
wires to the terminal board and secure the telephone
from the terminal board. Remove the telephone set
set in its enclosure.
chassis from the telephone set cover. Remove the
screws that hold the dial to the chassis, lift the dial out
Common Telephone `lkoubles
of the chassis, and remove the dial dust cover.
Disconnect the four leads from the screw terminals of
Some of the more common telephone set troubles
include (1) no dial tone, (2) dial impulses heard in the
Connect the four leads to the new dial, and secure
receiver while dialing, (3) poor transmission quality,
the dust cover on the dial. Insert the new dial in the
(4) low reception, (5) can transmit but cannot receive,
chassis, and secure the dial to the chassis. Secure the
(6) can receive but cannot transmit, (7) ringer does not
sound, (8) telephone set consistently dials the wrong
chassis on the telephone set cover, and reassemble the
number, (9) noisy connection, and (10) sidetone too
telephone set for normal operation.
loud. Procedures for analyzing these troubles and the
Ringer.-- To replace a ringer, remove the tele-
corrective actions you should take if they occur are
phone set from its enclosure and disconnect the
discussed briefly in the following paragraphs.
terminal wires from the terminal board. Remove the
NO DIAL TONE.-- If no dial tone is present, you
telephone set chassis from the telephone set cover.
must determine whether the telephone set, telephone
Unsolder the red lead and the green lead from the
line, or automatic dial telephone switchboard is the
ringer terminals. Remove the screws that hold the
cause of the problem. To isolate the problem, connect
ringer to the chassis and lift the ringer off the chassis.
a hand test telephone across the line. If a dial tone is
Mount the new ringer on the chassis and secure
present using the hand test telephone, then the problem
the ringer to the chassis. Solder the red lead and the
is in the telephone set. If the problem is in the set, it
green lead to the ringer. Secure the chassis on the
could be in the hookswitch, the receiver, the handset
telephone set cover and reassemble the telephone set
or desk set cord, or the transmission network. Once you
for normal operation.
isolate the problem, replace the defective component.
Dial Illumination Lamp.-- To replace the dial
If a dial tone is not present when checking the line
illumination lamp, remove the telephone set from its
with the hand test telephone, then the problem is either
enclosure. Remove the screw that secures the lamp
an open in the telephone line coming from the
holder to the chassis. Lift the lamp holder up until the
automatic dial telephone switchboard or in the
lamp is clear of the grommet, and then turn the lamp
switchboard itself. If the problem is found in the
holder over. Remove the lamp from the lamp holder
switchboard, you will need to refer to the switchboard
by pressing the lamp down gently and rotating it
counterclockwise approximately one-quarter turn.
DIAL PULSES HEARD WHILE DIALING.--
Install the new lamp in the lamp holder by pressing
Dial pulses heard in the receiver while you are dialing
the lamp down gently and rotating it clockwise
are usually the result of the hookswitch shunt spring
approximately one-quarter turn. Turn the lamp holder
contacts being out of adjustment. The contacts should
over and insert the new lamp in the grommet. Press
make when dialing. If the hookswitch contacts are
down until the lamp holder is against the grommet.
working properly, check the transmission network. If
Secure the lamp holder to the chassis. Remove the
there is a problem with the transmission network,
handset from its holder and check to see that the lamp
replace it. If the contacts are out of adjustment, adjust
the contacts by bending them.
Transmission Network. -- To replace the
POOR TRANSMISSION QUALITY.-- If a
transmission network, remove the telephone set from
telephone transmits poorly, the fault is probably in the
its enclosure and disconnect the terminal wires from
transmitter unit. One cause could be the carbon
the terminal board. Remove the 17 lead terminals from
granules inside the transmitter clinging together. You
the transmission network. Remove the two nuts and
can try and loosen the carbon granules in the
lockwashers that secure the transmission network to
transmitter by holding the handset in a horizontal