Teledyne 9110TH - Nitrogen Oxides Analyzer - Manual (Page 265)

Troubleshooting & Repair Model 9110TH NOx Analyzer
Teledyne Analytical Instruments 245
7.6. REPAIR PROCEDURES
This section contains some procedures that may need to be performed when a major
component of the analyzer requires repair or replacement. Other maintenance
procedures (e.g., replacement of regularly changed expendables) are discussed in
Section 6 (Maintenance) and are not listed here. TAI Technical Support may have a
more detailed service for some of the procedures listed here. Contact Technical
Support.
7.6.1. DISK-ON-MODULE REPLACEMENT
Replacing the Disk-on-Module (DOM) will cause loss of all DAS data; it also may
cause loss of some instrument configuration parameters unless the replacement DOM
carries the exact same firmware version. Whenever changing the version of installed
software, the memory must be reset. Failure to ensure that memory is reset can cause the
analyzer to malfunction, and invalidate measurements.
After the memory is reset, the A/D converter must be re-calibrated, and all information
collected in Step 1 below must be re-entered before the instrument will function
correctly. Also, zero and span calibration should be performed.
1. Document all analyzer parameters that may have been changed, such as range,
auto-cal, analog output, serial port and other settings before replacing the DOM
2. Turn off power to the instrument, fold down the rear panel by loosening the
mounting screws.
3. When looking at the electronic circuits from the back of the analyzer, locate the
Disk-on-Module in the right most socket of the CPU board.
4. The DOM should carry a label with firmware revision, date and initials of the
programmer.
5. Remove the nylon fastener that mounts the DOM over the CPU board, and lift the
DOM off the CPU. Do not bend the connector pins.
6. Install the new Disk-on-Module, making sure the notch at the end of the chip
matches the notch in the socket.
7. It may be necessary to straighten the pins somewhat to fit them into the socket.
Press the DOM all the way in and reinsert the offset clip.
8. Close the rear panel and turn on power to the machine.
9. If the replacement DOM carries a firmware revision, re-enter all of the setup
information.
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