3-4
2. POWER SUPPLY ON I/O BOARD
No 12V
Is VCC (14V) supplied to Q164
Collector?
YES
Check D124 on SMPS Board and
Replace
NO
Is 12.5V present at ZD151
& Q164
Base ?
YES
Check Q164 and Replace
NO
Check D126 on SMPS Board and
Replace
NO
Check Q162 and Replace
NO
Check the ‘PWR CTL H’ signal from
µ-COM
NO
Is VC
C (33V) supplied to Q162
Emitor ?
YES
Is 0V at Q162 Base ?
YES
Is there 5V at R171 and 0.7V at
Q156 Base?
YES
Check Q156 and Replace
YES