Bell System Practices TOUCH-A-MATIC 2872A1M Identification, Installation, Connections, Operation, And Maintenance page 55

ISS 5, SECTION 503-603-101
tTABLE N (Contd) 41
TROUBLE ANALYSIS - 2872AIM OR 2872A2M
, , , ,
TROUBLE
FAILURE ADDITIONAL SYMPTOM POSSIBLE CAUSE REMEDIAL ACTION
NUMBER
19 Speakerphone turns Black strap leads Insulate and store strap leads.
on but set does not were not lifted from
automatically dial PSB terminals 19 and
when memory but- 26 when option was
ton is depressed wired
Set dials when screw Precise dial tone not 1. Check CO line for presence of
(Wired for one- terminals 26 and 29 on present precise dial tone (350 Hz and
touch option) PSB are temporarily 440 Hz)
shorted 2. If correct dial tone is present,
replace dial tone detector PWB
assembly of D-180493 Kit of
Parts
Set does not dial from Defective logic Replace memory
memory when screw
terminals 26 and 29 on
PSB are temporarily
shorted
20 Automatic dialing Static discharge 1. Consult your Telco engineer
commences for no damage for proper grounding
apparent reason procedures
(wired for one- 2. Replace memory
touch option)
21 Calls not completed Automatic dialing is Marginal switchhook Remove handset more slowly
if handset is quickly terminated before all sequence between from handset cradle
taken off-hook while digits are dialed a-b and h-i contacts
automatically dialing
on a speakerphone
22 Set dials automati- Noise on line 1. Add 5pf capacitor between
cally but does not PSB-21 and PSB-26
wait for dial tone 2. Remove above capacitor and
(Wired for one- add resistor (10K_-50K_]) in
touch calling) series with (G-R) dial tone
detector input lead.
i
|
23 Cannot dial prop- MB7 relay does not Battery not plugged Plug battery in
erly from memory operate (no click heard) in (2872A2M tel set)
when on handset when memory button
Precise TOUCH- Make sure precise (350 Hz and
is depressed. TONE Q dial tone 440 Hz) dial tone is present
(Wired with dial tone
detector option) may not be present
Memory not securely Tighten memory mounting
mounted screws
Improper installation Check connections for D-180493
of dial tone detector, installation
D-180493
Same as above -- Improper connection 1. Check connector cable
Addition of strap lead to or defective 2. Replace memory
between PSB terminals memory
26 and 29 does not
correct problem
Addition of strap lead Defective memory Replace memory
between PSB terminals
26 and 29 corrects Defective dial tone Replace D-180493 dial tone
problem detector detector
Unknown Replace telephone set*
*Refer to 6.02 (4).
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