Realistic PRO-2022 - Memory Check; Memory Check Procedure

POWER ON
Enter (program)
150,000in
CHl
MEMORY CHECK
Note:
• Prior to checking the CPU System.
measure supply voltage to ICs. (See
schematic diagram.)
• While checking the following items, the
ICs can "Iatch up." If
50, push RESET
switch for about one second and then
continue.
Power switch OFF
Defective back-up circuit.
1C4 .
>------4 036
Power switch ON
NO Defective CPU control circuit,
Q33, and/or 041
I YES
Disconnect AC plug (or Ext.
power) and then insert them
after 1 hour.
Power switch ON
NO Defectiveback-up battery.
MEMORYcircuit is OK
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