PART SIX - SERVICE AND MAINTENANCE
SECTION 2 - TROUBLESHOOTING
Rev. 9-898
Model 692P
-53-
2.2 Resetting Instrument
to Factory-Default
Values
2.3 Isolating the Problem
Checking
Electrical Connections
Unusual conditions such as lightning (or high voltage power
surges), excessive electrical interference, or electrostatic
discharge could alter the memory, causing the instrument to
display false error messages or garbled data. To correct
this and restore normal operation, the instrument must be
reset. This procedure replaces all user-entered values with
factory-default values. Therefore, note your setup values in
Table B before resetting the instrument.
1. With display in pH measuring mode, press
EXAM/
CANCEL
key to place display in “examination” mode.
2. Press
NEXT
key until display indicates “SLOPE.” Then
press
NEXT
key once more to display “0000” (identifier
for security lock feature).
NOTE:
If security lock feature is in use (
LOCK
status in-
dicator is lit), it must be disabled at this time. Use
ï
ï
and
ñ
ñ
keys to make display indicate the
unlock code “1234,” and then press
ENTER
key.
3. With security lock feature disabled, use
ï
ï
and
ñ
ñ
keys to make display indicate the reset code “5678.”
4. Press
ENTER
key to enter reset code (display alter-
nately flashes “ERROR” and “Err 4” with a measured
value).
5. Press
ENTER
key once more to clear the “ERROR” and
“Err 4” message (only measured value is now dis-
played).
6. Recalibrate the instrument and enter noted setup values.
A few simple checks can determine if the measuring system
(sensor and instrument) is functioning properly. This section
is intended to isolate the problem to a particular element of
the system. If the conditions for each part of this section are
met, the system is operating properly. If not, Table G at the
end of this section lists common symptoms and causes to
help identify problems.
1. Verify that power is reaching appropriate instrument
terminals.
2. Push ribbon-cable connector halves together as tightly
as possible.
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