If the analyzer does not respond to keys being pressed or the knob being rotated, the fault could be either on the A3 Interface assembly or the A2 Controller assembly. To isolate the A2 Controller assembly, use the following procedure. This procedure tests the analyzer response over
1. Enter and run the following BASIC program.
10 OUTPUT718; "IP; SP 1MHz;"
20 WAIT 2 ! Wait 2 seconds
30 OUTPUT 718;"AT 70 DB;"
40 WAIT 2 ! Wait 2 seconds
50 OUTPUT718;"AT 30DB;"
60 WAIT 2 ! Wait 2 seconds
70 OUTPUT718;"AT IODB;"
80END
2.When the program runs, three or four clicks should be heard. This is the A9 Input Attenuator changing attenuation value.
3.If the display shows the analyzer to be in RMT and the ATTEN value displayed on the CRT changed according to the program, the A2 Controller assembly is working properly. Refer to Chapter 7, “ADC/Interface.”
4.If there was no response over
5.If there was an improper response (for example, the displayed ATTEN value changed but no clicks were heard), the A2 Controller is probably working properly.
6.Monitor A2U2 pin 2 with a logic probe for pulses while pressing a key and rotating the knob (RPG). This is the interrupt request signal for the keyboard and RPG.
7.If the interrupt request signal is always low, troubleshoot the A2 Controller assembly.
8.If the interrupt request signal is always high, the fault is on either the A3 Interface or AlAl Keyboard assembly.