Bell System Practices TOUCH-A-MATIC 2872A1M Identification, Installation, Connections, Operation, And Maintenance page 49

ISS 5, SECTION 503-603-101
0TABLE N 11
TROUBLE ANALYSIS - 2872AIM OR 2872A2M
, , ,,
TROUBLE
FAILURE ADDITIONAL SYMPTOM POSSIBLE CAUSE REMEDIAL ACTION
NUMBER
,,
1 Dead set on all lines Line lamp does not come Mounting cord Check cord insertion and
on when handset is taken improperly inserted connections
off-hook at equipment end
Line lamp comes on Bad connection 1. Check handset cord
when handset is taken between handset connections
off-hook and telephone set 2. Check handset jack
connections
Defective receiver Check handset
Unknown Replace telephone set*
Dial tone is not present Open tip or ring Check leads and connections from
when speakerphone is lead at line key contact strips
on
Dial tone is present when Defective line switch Replace telephone set*
speakerphone is on d-e or j-k contacts
2 Cannot transmit or Line lamp comes on Handset cord Check handset cord and/or
receive when off-hook improperly inserted handset
using handset into handset or jack
in telephone set
Dial tone present, but 12-pin connector 1. Check connector insertion
sidetone absent. No or dial not 2. Replace dial
audible TOUCH-TONE @ properly inserted
signal on pins on power
supply board
Defective 616B jack Replace 616B jack
Defective network Replace telephone set*
3 Cannot manually dial Clicking sounds or Bridged set off-hook Place bridged set on-hook
when off-hook damped TOUCH-TONE
signals heard when dial
buttons are depressed
Cannot hang up set.
No audible TOUCH- 20-pin power supply Check connector insertion
TONE signal present connector not pro-
perly inserted on pins
on memory PWB
Dial connectors not 1. Check connector insertion
properly inserted 2. Replace dial
Defective memory Replace memory
PWB
Unknown Replace telephone set*
Some TOUCH-TONE Static discharge 1. Consult Telco engineer for
dial frequencies damage proper grounding procedure
incorrect 2. Replace memory
4 Cannot manually dial Open or loose leads Check for proper insertion of
some digits when to dial contacts leads into 10-position dial
off-hook connector
Defective frequency Replace dial
contacts on dial
*Refer to 6.02 (4).
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