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Model 11180A
Section V
Table 5-1. Troubleshooting. (Cont'd)
a.
If not present, check the Reset pulse at IC36 pin 6
.
b.
If Reset is alright, check Computer Control Flip·
Flop at IC21 pins 1-6.
2. Check the Count pulse at A 1 IC37 pin 8
.
3.
Check the Count pulse at the Units Address Counter
IC32 pin 8
.
4. Check D output at IC32 pin 12. It
should
be
1/
10 the
count rate
.
5. Check Tens Address Counter at output pads 34, 35 and
36.
a.
If output bad, check input at A21C19 pin 2 for a
.
5 µs low pulse. It should be in sync with the
negative edge of D output of Units Address Counter
b. Check both flip-flops in IC43 and IC44
.
c
.
If Counter counts past 50 or 1/0 flip-flop does not
work
.
1) Check the Reset pulse at A21C45 pin 8 and I C41
pin
13.
NOTE: This Reset pulse ends Jump Command
and enables Measurement Hold command
.
2) Check the Preset and Reset gating IC40-42.
B. If A1, 81, Cl or 01 is bad at the Storage output, check
A 1 IC29 and IC30
,
L25 through L27, and A21C15 through
IC18 .
C.
Preset Trigger problem.
1. Check input monostables IC41 and IC42
.
Each should
produce a low pulse of approximately 1 µs .
2. Check the Preset and Reset gating IC40-42.
3
.
Check for a 1 µslow Preset pulse at A21C20 pin 8.
4. Check· the Input Cycle Hold override flip-flop IC20 pins
1-6.
5. Check the Units Counter preset at A 1 IC31 pin 6.
D. Input Cycle Hold problem.
1.
Check at input pads 52 and 53.
2. Replace IC44.
E. Status Flag problem.
1. Check 1/0 flip-flop IC44
.
2. Check buffers IC18 pins 8 and 9. IC37 pins 11-13, and
IC38 pins 3-6.
V. Scanner-Storage problem
.
A. Check for proper operation with a 3481, 82 or 84 plug-in,
then decide on the major problem with 3485A operation as
follows:
Major Scanner-Storage
problems.
1. "Odd" * number channel scan with no output: no
output with the Scanner limit less than the Storage limit
with Scanner Control Enable signal true (low).
2. Skip loss: with the Storage limit equal to the Scanner
limit, the number of output printings does not equal the
Storage limit
.
3.
Amplifier-Zero loss
:
no printout of the Scanner ampli-
fier zero reading. Note
:
the Scanner amp zero reading
(the last reading
address of 00 printed) is
given only when an "odd" number of readings is
scanned
.
4. Sync
loss:
Scanner
reading
(Channel number) not equal
to Storage address .
*An "odd" Scanner limit number is one not equal to the
Storage limit.
B.
"Odd" number channel scan with no output.
1. Check that the Scanner Control Enable line is low.
2.
Check the Scanner Home Flag
.
a.
It shou Id go low at the end of a scan
.
b.
It should produce a high level at A 1-IC34 pin
13.
3
.
Pin 12 of A1-IC34
should
be high
.
See "Skip loss' major
problem
if
it is not high
.
4.
Check gate A2-IC31 pins 8
through
13.
Pins 9, 12 and
13 should be high; pin
10
should have a high pulse at
Scanner Home Flag.
5.
An
"odd"
scan should cause a jump command.
C. Skip loss.
1. Check for a high level on the Panel Transfer line during
the output cycle
.
2.
Check the Skip flip-flop A 1-IC34 pins 1 through 6.
3
.
Check for reset of the Skip flip-flop after one reading is
taken.
D. Amplifier-Zero
loss.
1. Check Amplifier Zero flip-flop A 1-IC35 pins 8 through
13, and gate IC34 pins 8 through 10.
2
.
Check LI 1.
E. Sync loss:
1.
Check "Odd number channel scan with no output"
major problem
.
2. Check output pulses at A 1-IC39 pins 7 and
10.
IC39 pin 7
IC39 pin 10
Pin 7 pulse is triggered by the Panel Transfer at the end of an
output cycle. Pin 10 pulse is triggered by the Scanner Home
Flag.
5-3
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