Advanced Instruments 3900, Service Manual

Page: 128 / 184

5. Remove all mounting screws (D) from the
front panel of the instrument, and pull the
panel down and out.
6. Locate the reservoir tank thermistor probe
connection at the PCB board set (E).
Disconnect the reservoir tank thermistor
probe from J6 of the 4C3450 PCB.
7. Release the reservoir tank thermistor probe
cable from the cable ties that secure it to
other system wire harnessing.
8. On the reservoir tank wall, remove the
nylon cable clamp and fasteners securing
the reservoir tank thermistor probe in place
(F).
9. Gently slide the reservoir tank thermistor
probe out of the reservoir tank probe
opening and wrap the end coated with
thermal compound in a paper towel.
10. Apply additional thermal compound
(supplied) to the reservoir tank probe
opening by inserting the applicator into the
cavity as far as possible before applying
force to the plunger. Slowly back the
applicator out of the opening while
dispensing thermal compound to ensure
the cavity is properly filled.
11. Insert the replacement reservoir tank
thermistor probe into the thermal
compound filled reservoir tank probe
opening as far as possible. While keeping
inward pressure on the reservoir tank
thermistor probe, secure the probe cable to
the reservoir tank wall using the nylon
cable clamp and hardware removed earlier.
12. Route the free end of the reservoir tank
thermistor probe cable under the sample
deck and connect to J6 of the 4C3450
PCB.
13. Secure the reservoir tank thermistor probe
cable to the system wire harness cabling
using the cable ties removed earlier. If the
cable ties removed earlier are not the
reusable type, use the twist lock cable ties
provided.
4C3P341 Rev2
(4C35/3905 Service Manual)
Page 2 of 3
C
D
LED D5 E