Advanced Bilirubin Stat-Analyzer BR2, Service Manual, Page: 32 / 69

32
The Advanced® Model BR2 Service Manual
5. One segment of a dis-
play digit not working.
a. Temporarily connect a jumper
from pin 37 of IC4 to +5 V to
test all digit segments.
b. Ribbon cable J1-J2 continuity
and connections.
Symptom Check Suggested Action
a. Replace defective display module 16, 17
or 18.
b. Replace ribbon cable J1-J2.
6. Readout cannot be
zeroed using the oper-
ating procedure in the
User’s Guide, Chapter
2, Instrument
Operation .
a. Optical lamp I1 and the lamp
circuit.
b. Pin 6 of IC5 for approximately -
80 mV.
c. Pin 6 of IC6 for approximately -
40 mV.
d. Pin 3 of IC7 for zero output
when the GAIN potentiometer
outputs at TP540 and 454 are
balanced at 20 mV.
e. Pin 36 of IC4 for +1 V with S2
in the NORMAL position and its
arm temporarily grounded. If no
S2, short jumper wire at S2.
a. Replace I1, IC1, Q1, or D4.
b. Replace IC5.
c. Replace IC6.
d. Replace IC7, R48, or J1-J2 ribbon cable.
e. Replace IC4.
7. Readout cannot be cal-
ibrated.
a. Review User’s Guide Chapter 2,
Instrument Operation , sections
A and B.
b. The cuvette.
c. The standard.
d. The instrument.
a. Correct technique.
b. Try a clean cuvette.
c. Try another standard.
d. See item 9, below.
8. Readout cannot be cal-
ibrated to read your
standard correctly.
a. Pin 3 of IC7 for approximately
+0.4 V.
b. The arm of S2 (the TEST/NOR-
MAL switch near the center of
the Main board) for approxi-
0.4 V. If no S2, use
jumper wire at location of S2.
c. The optical filters for damage or
deterioration.
d. R45, R53.
a. Replace IC7.
b. Replace R47 (the Calibrate potentiometer
on the Display board).
c. Replace the optical filters.