Motorola R-2001A, Service Manual

Page: 81 / 220

Table 5-6. System Troubleshooting (Cont)
Test Paragraph Fault Troubleshooting Procedure
5-132 System won't turn on
5-132
5-133
5-133
5-134
5-135
System turns on, but no display
on the CRT for any display
mode
More than one key is inopera-
tive or has the wrong effect
Only one key is inoperative
Any part of the nonvolatile
memory fails to remember
No DPL (modulation) signal on
CRT
1. Disconnect the high voltage supply from the
low voltage supply at A10P1. Check for
+7.9 VDC at pin 1 of J2 on the low voltage
supply and for+12 VDC at pin 2. If either volt-
age is not present replace the low voltage
supply (A1).
2. Reconnect the low voltage/high voltage inter-
face and check for a n9 VDC at C15
on the high voltage supply. (C15 isafeedthru
cap on the high voltage supply and can be
reached from the top side just beyond the
CRT socket.)
CAUTION
There is 110V on the rear panel connector even
when the power switch is turned off.
If 9 volts is not present replace the high
voltage supply (A1).
3. If items 1 and 2 check okay replace the low
voltage supply (A1).
1. Check for presence of high voltage by dis-
connecting the CRT anode lead and arcing
it to the chassis. If no arc, replace the high
voltage supply.
2. If the high voltage supply is okay, replace the
CRT.
1. Replace the Processor Module (A9).
1. Replace the defective key switch.
1. Replace the Processor module (A9).
1. Check TP1 of the Audio Synthesizer for the
presence of the DPL signal. If not present
replace the Audio Synthesizer module.
2. Check for the DPL signal on pin 64 of the
Audio Synthesizer. If not present replace the
IEEE Interface module (A8), or check for the
presence of the jumpers on J8 for the standard
unit.
5-38