Ricoh FT4227 Manual page 574

OTHERS
10.8 DC POWER SUPPLY BOARD REPLACEMENT
NOTE: 1. Check the fuses (F1, F2, F3, and F4) on the board before
determining that the dc power supply board is defective.
2. When checking if the dc power supply board is defctive or not
by installing the board on another machine, wait for 10 minutes
before turning on the main switch. Because if the over voltage
protection circuit functions, the dc power supply board cuts its
output and it takes a maximum of 10 minutes to recover by
discharging the capacitors.
1. Turn off the main switch and unplug the power cord.
2. Remove the rear cover.
3. Remove the dc power supply board [A] (5 screws and 4 connectors).
[A]
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12 February 1992