10.2.3Checking the keyboard

absence of these actions will usually indicate either a CPU or Display failure. To determine which module is defective, perform the following procedure:

1.Turn off power.

2.Remove the ribbon cable from the CPU board to the Display;

3.Turn Power on.

4.A cursor character should appear in the upper left corner of the display. If it does not, the display is defective and should be replaced. If the cursor does appear, it is probable that the CPU is faulty.

10.2.3Checking the keyboard

During normal Analyzer operation, depressing the right most key of the keyboard should cause a change of display modes. If it does not, check:

-Cable connections;

-CPU and Display operation (see Section 10.2.2)

If these checks are satisfactory, it is probable that the keyboard is defective and should be replaced.

10.3 Troubleshooting using warning messages

The most common and/or serious instrument failures will result in a warning message (or messages) being displayed on the front panel. Table 10-1 below lists the warning messages which the Analyzer may display, along with their meaning and the recommended corrective action. It should be noted that if multiple (more than 2 or 3) warning messages occur at the same time, it is often an indication that some fundamental analyzer sub-system (power supply, V/F board, CPU) has failed rather than an indication of the multiple failures referenced by the warnings. In this situation, it is recommended that proper operation of power supplies (see Section 10.6.4) and the V/F Board (see Section 10.6.3) be confirmed before addressing the specific warning messages.

WARNING MESSAGES

Warning Message

Meaning

Corrective Action

SOURCE WARNING

The CO REF value is

Check and adjust the

 

greater than 5000 mV or

Sync Demodulator and

 

less than 2500 mV

optical alignment as

 

 

described in Section

 

 

10.6.6 and 10.6.8

SYNC ERROR

No modulation is present

Check IR source, IR

 

on the output of the IR

detector/pre-amp, and

 

detector.

Opto interrupter

P/N 02163G1 Teledyne API Model 300 CO Analyzer Instruction Manual - Page 85

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Teledyne 300 Troubleshooting using warning messages, 10.2.3Checking the keyboard, Corrective Action, Warning Messages