Teledyne 501 TRS, Operation Manual, Page: 77 / 111

Teledyne API - T102/501 TRS, Addendum to T101 Operation Manual TROUBLESHOOTING and REPAIR
75
1. Power down the analyzer, disconnect the power cord, remove the cover
and disconnect all pneumatic and electrical connections from the sensor
assembly.
2. Remove the entire sensor module assembly from the analyzer.
3. Remove the reaction cell assembly.
4. Remove the two connectors (PMT Output Connector and the PMT Power
Supply and Aux. Connector) on the PMT housing end plate facing
towards the front panel.
5. Remove the end plate itself (4 screws with plastic washers).
6. Remove and discard all of the desiccant bags inside the PMT housing
end plate.
7. Along with the plate, slide out the OPTIC TEST (O-Test) LED and the
thermistor (PMT Temperature Sensor).
The thermistor will be coated with a white, thermal conducting paste.
Do not contaminate the inside of the housing or the PMT tube with this
paste.
8. Unscrew the PMT assembly. It is held to the cold block by two plastic
screws.
Because the threads of the plastic screws are easily damaged it is
highly recommended to use new screws when reassembling the unit.
9. Carefully take out the assembly consisting of the HVPS, the insulation
gasket and the PMT.
10. Change the PMT or the HVPS or both, clean the PMT glass tube with a
clean, anti-static wipe and do not touch it after cleaning.
11. If the cold block or TEC is to be changed disconnect the TEC driver
board from the preamplifier board.
a. Remove the cooler fan duct (4 screws on its side) including the
driver board.
b. Disconnect the driver board from the TEC and set the sub-assembly
aside.
c. Remove the end plate with the cooling fins (4 screws) and slide out
the PMT cold block assembly, which contains the TEC.
d. Unscrew the TEC from the cooling fins and the cold block and
replace it with a new unit.
12. Re-assemble the TEC subassembly in reverse order.
07267B DCN6485