Advanced Bilirubin Stat-Analyzer BR2, Service Manual, Page: 29 / 69

29
The Advanced® Model BR2 Service Manual
Left X X X X X X X
S3 Position
Label 540 454 DIR.POT LAMP D4 REF +5 -15 +15
mg/dl Readout
(within 5%) 1.7 1.7 2.0-4.0 33.5 6.9 5.0 15.0 15.0
Circuit to
Troubleshoot Signal Conditioning Lamp Power Supply
Right
Internal Self-Diagnosis Voltage Checks
NOTE Beginning with instruments produced
in 2016 or instruments having the
main PCB, BR2100 replaced in
2016, the built-in test circuit will not
be available.
The built-in self-diagnosis circuit enables the
service technician to use the DVM circuit of
the BR2 to measure and display (in place of
the mg/dl or µmol/1 readout) several impor-
tant circuit voltages.
Tools needed: Flat-bladed screwdriver, stop-
watch.
Warning-Hazardous Voltage
Warning-Internal components may be
damaged by static electricity.
1. Shut off and unplug the BR2.
2. Remove the four screws from both sides
of the BR2 and pull the instrument cover
straight up and off.
3. Plug in and power the instrument careful-
ly so that you do not contact the AC line
voltage between the fuse holder and
power transformer.
4. Press the Total button.
5. Switch S2 (the NORMAL/TEST toggle
switch near the center of the Main board)
from NORMAL to TEST position.
6. Switch S3 (the long selector switch near
the left center of the Main board) slowly
from right to left, one position at a time,
while monitoring the mg/dl display. The
display should read as shown in the chart
below (within ±5%).
7. Press the Direct button, move S3 back to
the 454 position and recheck the readout.
The 454 position readout listed in the
table above should also be indicated in
the Direct mode. If not, troubleshoot the
R43 arm “Direct” reference voltage input
to R42 (see chapter 6, Wiring Diagram
BR2003).
NOTE Be sure to return S2 to NORMAL
and S3 to the far right (+15) position
as soon as this test is finished.
8. Shut off and unplug the BR2. Replace
the instrument cover.