HP 5300A - Page 42

Model 5300A
Maintenance
Figure 5-3C. Display Checks (Continued)
DISPLAY
ROTATES
000000
999999
BLANK
DISPLAY
CHECK DIGIT
SELECT Z
FOR LOW LEVEL
TO CARO “B"
®
DISPLAY IS
ALL ZERO’S
WITH “C”’
LAMP ON
PUSH RESET
BUTTON, FRONT
PANEL
1. “C” LAMP GOES
BLANK OISPLAY
POSSIBLE
RESET
PROBLEM
CHECK COUNTER
INPUT U3 (14)
SEE FIG 4-6A
2 COOE
POSSIBLE OPEN
TRACES.
BAD
CONNECTOR
CHECK COUNTER
INPUT AT U5(5)
SEE FIG 4-64
2 CODE
DISPLAY IS
ROTATING ATA
FASTER THAN
TSEC. RATE
CHECK DIGIT
SELECT “X" ANO
“Y" FOR
POSSIBLE
SHORT
EVEN OR
OOD NUMBERS
CYCLING
CHECK DATAA
FOR OTO+15V
PULSES
DISPLAY IS
ALL ZERO’S
“C" LAMP OFF
CHECK MANUAL
RESET CODE
FOR LOW
out
2. CHECK U3(14)
(SEE FIG 4-6A)
3. CHECK +6 V U3
CHECK DATA (12)(13)
AB,C,D AT
U3. (SEE TABLE
5-2, 5-3) CHECK
ASSOCIATED
AREA-PC CHANGE
BOARD U3
CONNECTOR
5-31. Insert Test 6. Checks U3, U4, U5. Refer to Fig-
ure 5-4B. SAMPLE RATE set to 1/2 cw from power
OFF. “C” lamp cycles, ‘“*” cycles. Display should
read at turn on 000007, 1 second later 000008, and 10
seconds later 000009.
5-32. Insert Test 7. Checks U3, U4, U5. Refer to Fig-
ure 5-4C. Turn sample rate 1/2 cw. Display should
be 10.0000 MHz +1 count. ‘“C” lamp cycling.
5-33. Insert Test 8. Checks Annunciators and
Decimal Points 1 through 5. Display should be
10.0000 MHz +1 count. ‘“C” lamp cycling.
5-34. By using a shorting plug (HP Part No. 5080-
0058) to connect various points on test card B, test 8,
the Annunciators (Hz, M, S, K, uw) and decimal points
1 through 5 can be verified. See Figure 8-2 for sche-
matic information. To light a particular annunciator
or decimal point, plug shorting bar into the corres-
ponding holes for that annunciator or decimal point.
“C” lamp off.
CHANGE CHANGE
US U2
CHANGE
US
5-35. Diagnostic Test Card “C”
5-36. Insert Test 9 through 12. To use Diagnostic
Test
Card
“C,”
connect
this
card
through
the
inter-
face
card,
HP
Part
No.
05300-60004,
to
5300A
main-
frame
AlJ1
connector.
Prior
to
each
test,
press
RESET.
5-37. These tests check U3 and U4 by programming
the Time Base input codes to provide Time Base out-
put signals in decade steps.
5-38. Test No. 9. Fixed program tests the 10-second
Time Base output. Display should accumulate one
count every 10 seconds starting with digit 0, least-
significant digit. ‘“(C” lamp on.
5-39. Test No. 10. Fixed program tests the l-second
Time Base output. Display should accumulate one
count every second starting with digit 0, least-signifi-
cant digit. “C” lamp on.
5-7