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Section V
Model l l l 80A
Table 5-1. Troubleshooting. (Cont'd)
11. I BCD Control problem. (Figure 7-1)
C. Printer Hold problem.
5-2
A. Preliminary Checks.
1.
Check the Printer Hold circuitry shown on Figure 7-4
.
1. The 3480 will not sample.
D
.
Encode problem.
a.
Check that Inhibit signal at pad 51 on 11180A A2 is
1. Check the Encode circuitry shown on Figure 7-8.
low.
b. Check that Memory signal at IC22 pin 4 on A2 is
Ill. Storage Control problem.
low.
c.
Check the Printer Hold circuit, Figure
7-4.
2.
The Clock Oscillator is not running or not gated by the
3480 sample rate. Check A21C36 pin 8.
==
1
ms
~
:=
2sOkH
z
-i
l-3µs-ol
_n____n_
1 µs
-+--I
a.
If the oscillator is not running, check the Turn-On
circuit, Clock Gating Flip-Flop, Clock Oscillator,
drive IC19 pins 10and 11,
L30,
and IC33 pins 10-13
on Al
.
b.
If the oscillator is running but not gated, check the
Clock Gating Flip-Flop, IC19 pins 12 and 13, L29,
and A 1 IC33 pins 8 and 9.
3. Check the basic Timing Generator, Figure 7-2.
a.
The basic Timing Cycle is started by a high level at
A21C38 pin
12.
This is gated into a pulse by IC37
pins 1-6 and IC34 pins 4-6
.
b. The timing sequence is
:
A
_J
I
I
I
B
R
T
CLK
11 186A · 8 -
26~6
B. No Storage Flag.
1.
Check that Memory signal at A21C48 pin 2 is low.
A
.
Unable to turn on Storage.
1.
Check that A21C34 pin 11 is low. This is the Scanner
amplifier-zero Storage override.
2
.
Check Storage Enable circuitry on Figure 7-2
.
B. Jump Command problem.
1. Check IC33 monostable on Jump line. Output pulse:
=:
1 µs
.
2. Check Jump flip-flop, IC31 and IC32.
3.
Check basic Timing Generator Counter circuitry, Figure
7·2
.
C.
Limits problem.
1. If Jump Command works, check IC29 Limit inverters.
2.
If IC29 is alright, replace IC30.
D
.
Storage Flag problem.
1.
Check Storage Flag in IBCD
mode.
2. Replace A21C23.
E. Measurement Hold Problem.
1. Check basic Timing Generator circuitry
,
Measurement
Hold flip-flop and inverter I C33 pins 11-13.
F
.
Dump Hold problem
1. Check Dump Hold circuitry, Figure 7·6.
2. Check the timing pulse at A21C24
pi
n
1.
(4 µsec pulse).
IV. Address Counter checkout
.
3.
Check the Clock waveform at A21C24 pin 2. See
Paragraph 2A2.
4. Check that Turn-On signal at A21C24 pin 12 is high
.
5
.
Check the Storage Flag flip-flop and output buffer
.
Do this check at 1 kHz sample rate in IBCD mode.
A. The basic Count pulse is generated by the Timing Generator
and Decoding, A21C35 and
IC34.
1. Check the Count pulse at IC46 pin
12.
. . .
'l.'
•
i
]
'
]
L
.
:]
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