HP 5300A - Page 40

DISPLAY 4S
ev=a0
CHECK
R/L LINE
DISPLAY IS
543210
DISPLAY IS
oH8 2110
DISPLAY 1S
553311
CHECK DIGIT
ADDRESS “X"
(SEE Fig. 4-6A)
Any row and/or any
group of "dots" missing.
Any or all rows always
on.
Any or all columns mis-
sing (vertical lines).
Two adjacent columns
show mirror image.
One or more ALAIDS7
diodes not on.
Incorrect diodes glowing
dimly
Very bright half-digit
"on",
Uneven diode
brightness.
Decimal point shifts
incorrectly and wrong
annunciator lights.
Display is all zeros"
for tests 1, 2 and 3, but
works with test 4.
Figure 5-3A.
DISPLAY iS
442200
CHECK
DATA “A”
TABLE 5-2
CHECK INPUT
TO U2(17),
A1J1(45) AND
U3(15) OR
POSSIBLE SHORTS
ON PC BOARD
DISPLAY tS
541010
CHECK DIGIT
ADDRESS “Y”
(SEE FIG 4-6A)
CHANGE
Display Checks
DISPLAY IS DISPLAY IS
763232 103210
CHECK CHECK DIGIT
DATA “B” ADORESS“2”
TABLE 5-2 (SEE FIG 4-6A)
CHECK INPUT
TO U2(14),
A1J1(44), CHANGE
U3(16) OR ui
POSSIBLE SHORTS) OR U3
ON PC BOARD
DISPLAY IS
§47654
CHECK DATA “C”
TABLE 5-2
CHECK INPUT
TO U2(15), -
A1J1(43),U3(1)
OR POSSIBLE
SHORTS ON
PC BOARD
Model 5300A
Maintenance
DISPLAY iS
- 2298
CHECK
DATA “D”
TABLE 5-2
SHOULD BE
LOW. CHECK
U2(16) AND
PC TRACE FOR
POSSIBLE OPEN
CIRCUIT
See Table 4-1 and Figure 4-5A/B,
monitor U2 level with an oscillo-
scope thru a 2209 resistor to gnd.
See Table 5-3 and mointor U2 level
change with oscilloscope.
See Figure 4-6-A and monitor Al
outputs with oscilloscope.
See Figure 4-6-A and monitor Al
outputs with oscilloscope.
See Fig. 4-5 and Table 4-1, monitor
output codes vs. input codes onU2.
Monitor U1(13) with oscilloscope.
Should be 1.4 V p-p, sawtooth
waveform, 4 kHz to 8 kHz.
Check BCD lines on U3; if all are
low, change U3.
U2, Mechanical connections at U2,
A1A1DS87 or A1A1DS7 circuit foil.
U2 Mechanical connections at U2,
A1AIDS7 circuit foil.
U1, C16, Q6 to Q17 Mechanical
connections at U1, A1lA1DST.
U1, short between A1A1DS7
adjacent pins.
A1A1DS7, U2, poor socket connec -
tion on U2 or A1A1DS7.
U2, A1A1DS7
U1, C17
U2
Incorrect exponent from U5.
Change U5.
U3