Teletype SA110 Checkout And Troubleshooting page 11

ISS 1, SECTION 578-200-300
SAll0 PARITY FAILURE DETECTOR TROUBLESHOOTING CHART (continued)
NO.
TROUBLE INDICATION ANALYSIS AND RECOMMENDED ACTION
6. Errors indicated continuously a.
If SAllO input is from a 33 type set, cut strap Con
(output copy good).
card MC402-04.
b. If strap C is open, or if SAll0 input is not from a 33 type
set, check terminals 7, 8, and 9 on card MC402-04 to
determine if they are strapped for the type of parity being
received ( 8 and 9 strapped for even parity check - alarm on
odd parity, 8 and 7 strapped for odd parity check - alarm on
even parity). Change strapping if incorrect.
c. If strapping of terminals 7, 8, and 9 is correct, card
MC402-04 is defective. Repair or replace card MC402-04
(TP322402-04 ).
7.
Errors indicated continuously
a.
Check straps A and Band terminals 10, 11, and 12 on
(output copy garbled). card MC402-04 to determine if they are strapped for the
unit code being received (Section 578-200-200 and
8538WD). Change strapping if incorrect.
b. If straps A and Band terminals 10, 11, and 12 are strapped
correctly, either card MC402-04 (TP322402-04) or MC405
(TP322405) is defective. Replace card MC402-04 first to isolate
trouble or replace entire SAll0.
(
8. False parity or significant Card MC402-04 is defective. Repair or replace card MC402-04
distortion error indications (not (TP322402-04).
continuous, output copy good).
9. Indicator lamp does not light, a. Check lamp bulb. Replace bulb if burned out.
but counter advances for each
error. b. If bulb is good, check SAll0 connections for lamp and
counter (8716WD or 8717WD). Look for loose connections or
connections made to wrong terminals. Correct any faults
found.
c. If lamp and counter connections are good, check wiring
(
of bypass switch and indicator assembly for lamp and
counter (8566WD or 8567WD). Correct any faults found.
d. For the SAll0 ED only, check to be sure that strap C
on card MC405 is open and strap Dis closed (except 2400
baud operation). Change strapping if incorrect.
e.
If straps C and D are correct, relay Kl on card MC405 is
defective. Replace it or replace card MC405 (TP322405).
10. Indicator lamp lights, but a.
Check terminals 31, 32, and 33 on card MC405 to determine
counter does not advance (SAll0 BB, if they are strapped for -14 volts as required (Section
SAll0 CB, or SAll0 EB only).
578-200-200). If connections are reversed, strap as
required. Also replace diode CRl (8716WD, 8566WD, 8717WD,
8567WD) on the counter, which was destroyed by the improper
voltage.
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