5.2
Diagnostic
Software,
continued
•
Random characters:
Random or nonsense characters usually indicate a faulty microprocessor PCB.
Replace the microprocessor and re-test (see section 6.3.8).
In both cases above, if the display still does not work properly, refer to section 6.3.9 and replace it.
4.
Press the Standby Button and advance to the second page of the service mode. Verify that CRC 55947 and
the proper line rate are displayed. Proceed to the next step.
If 55947 is not displayed, cycle the Generator power and re-attempt this test. If the problem persists,
replace the microprocessor PCB (see section 6.3.8).
If the line rate is inappropriate, refer to section 4.3 to change it.
5.
Press the Standby Button and advance to the third page of the service mode. In this page,
the relative current, voltage, frequency, selected power level, and mode are displayed. Verify
that these values are within the normal operating parameters. Proceed to the next step.
From left to right, the display should indicate the following normal operating parameters:
Relative current
Between 40 and 50 (mA)
Relative DC voltage
Between 15 and 25 (v)
Output frequency
Between 50,000 Hz and 60,000 Hz
Selected Power level
Between 1 and 5
Operating Mode
6 (Refer to the value in the lower left hand
corner of the function boxes in Appendix A)
Possible Problems:
•
Display voltage or current is low (< 15 or < 40 respectively):
The high voltage AC is not reaching the generator PCB or the generator PCB's switching power
supply is not working. Verify that the high voltage AC is at the generator PCB (see section 6.3.5). If
no AC is present, check the high voltage wiring, transformer, and fusing (see sections 6.3.5 and 6.3.2).
If AC is present, replace the generator PCB (see section 6.3.6).
•
Display voltage or current is high (> 25 or > 50 respectively):
The power regulation circuit on the generator PCB is not functioning properly.
See section 6.3.6 and replace the PCB.
•
Display frequency is high or low (> 60,000 or < 50,000):
The frequency control circuit on the generator PCB is not functioning properly.
See section 6.3.6 and replace the PCB.
6.
Verify that the READY LED is now illuminated. Proceed to the next step.
If the READY LED does not come on, either the LED itself or the interlock circuitry on the keyboard PCB
is faulty. In either case, replace the keyboard and re-test (see section 6.3.7).
7.
Verify that pushing either pedal on the Foot Switch causes the READY LED to go out.
If the READY LED does not go out while pressing either foot pedal, inspect the cabling leading from the
keyboard to the Foot Switch connector on the back of the Generator (see section 6.3.7). If the cabling
appears intact, replace the Foot Switch cable and re-test (see section 6.3.10). If the problem persists,
replace the keyboard PCB (see section 6.3.7).
14
Chapter 5 - Upper Level Diagnostics
continued
