The Advanced
®
3D3/4D3 Service Manual
The following situations indicate a problem
with either the probes or the cooling assem-
bly:
Hitachi Processor
The resistance reading is >10,000 ohms
on either channel without a target temper-
ature [>5,200 on 4D3 sample channel].
This reading indicates an open circuit.
The resistance on either channel does not
increase from 4,990 ohms after the target
temperature has been set.
Intel Processor
The resistance reading is replaced by the
number 0. Scrolling from right to left
indicates an open circuit.
The target temperature cannot be reached,
but probe readings that vary around ambi-
ent indicate a cooling system problem.
To determine if a faulty probe is causing the
problem:
1. Disconnect the probe from the main
board.
2. Place a 6 Kohm fixed resistor across pins
1 and 2.
3. If the resistance display changes to
approximately 6,000 ohms, replace the
probe.
If the resistance does not change, replace
the main control board or application
board.
If the resistance on both channels does not
increase from 4,990 ohms on Hitachi proces-
sor systems, or if the temperature reads
approximately ambient on Intel processor sys-
tems while a target temperature is set, the sit-
uation indicates a problem with either the
cooling assembly, main control board, or
application board.
To determine which component is faulty:
1. Remove the empty tube from the freezing
chamber.
2. Set the target temperature to -8.
3. Raise the head manually and place a ther-
mometer inside of the freezing chamber.
4. If the temperature inside the freezing
chamber drops to approximately -8ºC, the
cooling assembly is working, and the
main control board/application board
needs to be replaced.
If the temperature remains at room tem-
perature, replace the cooling assembly.
Note: When the A/D channel is open, there is
a thirty-second delay in response to
any resistance change.
CAUTION: If the A/D test sample freezes,
allow it to thaw before attempt-
ing to remove the sample probe.
Sample Bin Setting
If you do not know the sample bin number, or
if you want to verify the sample bin number:
1. Turn on the instrument. If there is a
Supervisor/Operator keyswitch, turn it to
the Supervisor position (if required).
2. Press TEST. Press < or > to select
“Probe Bin Test”, and then press
START.
3. Place a sample of Probe Bin-Setting Fluid
into the freezing chamber.
4. At “[START] Ready?”, press START.
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