Teledyne 6200E - Sulfides Analyzer - Manual (Page 257)

Model 6200E Instruction Manual TROUBLESHOOTING & REPAIR
M6200E Rev: A1 257
11.5.8.4. Control Inputs
The control input bits can be tested by the following procedure:
1. Connect a jumper from the +5 V pin on the STATUS connector to the +5 V on the CONTROL
IN connector.
2. Connect a second jumper from the ‘-‘ pin on the STATUS connector to the A pin on the
CONTROL IN connector. The instrument should switch from SAMPLE mode to ZERO CAL R
mode.
3. Connect a second jumper from the ‘-‘ pin on the STATUS connector to the B pin on the
CONTROL IN connector. The instrument should switch from SAMPLE mode to SPAN CAL R
mode.
In each case, the M6200E should return to SAMPLE mode when the jumper is removed.
11.5.9. CPU
There are two major types of CPU board failures, a complete failure and a failure associated with
the Disk-On-Chip (DOC). If either of these failures occur, contact the factory.
• For complete failures, assuming that the power supplies are operating properly and the
wiring is intact, the CPU is faulty if on power-on:
• The watchdog LED on the motherboard is not flashing
• There is no activity from the primary RS-232 port (COM1) on the rear panel even if “?
” is pressed. Note that the RS-232 port has programmable baud rates from 200
to 115200 baud. Since the CPU board remembers the programmed baud rate even
when power is off, this means that there is no default baud rate for the port when the
instrument boots up, the rate will be whatever it was last programmed to be. In some
cases, configuration memory might be corrupted, and the baud rate could be a random
unrelated value. For these reasons, it is best to test all possible baud rates when
performing this test. See the RS-2323 Communication section below, for more details
regarding port configuration.
In some rare circumstances, this failure may be caused by a bad IC on the motherboard,
specifically U57, the large, 44 pin device on the lower right hand side of the board. If this is true,
removing U57 from its socket will allow the instrument to start up but the measurements will be
invalid.
• If the analyzer stops during initialization (the vacuum fluorescent display shows some
text), it is likely that the DOC, the firmware or the configuration and data files have been
corrupted.
11.5.10. RS-232 Communication
11.5.10.1. General RS-232 Troubleshooting
Teledyne Analytical Instruments analyzers use the RS-232 protocol as the standard, serial
communications protocol. RS-232 is a versatile standard, which has been used for many years
but, at times, is difficult to configure. Teledyne Analytical Instruments conforms to the standard