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Real time clock installation instructions for Amiga A4000D
Fitting and testing a replacement Ricoh RP5C01 real time clock IC to an Amiga A4000D Anthony Hoffman June 2008
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Power off the computer, disconnect all cables and move the computer to a brightly
illuminated desk to be able to work on it.
Lift the top case by removing the two screws in the rear upper corners which will
allow the case to slide backwards slightly, then upwards.
Locate the real time clock, U178, which is on the outer edge of the main board, close to the
joystick connector and just to the side of the memory slots. You may need to remove some or all
Zorro expansion cards to be able to access this area of the main board.
By default the clock is soldered into the main board, though your main board may have been fitted
with a socket. Replacing a soldered in device is not covered by these instructions, only replacing
a socketed device is described here.
If an existing clock requires removal, use a small flat blade screwdriver between the underside of
the clock and the socket, working from the two narrow sides to gradually lift the device from the
socket.
Before fitting the new clock, ensure none of the pins are bent, and all the pins are pointing
vertically downwards.
Carefully press the new clock into the socket, making sure the polarity is correct, as shown below
Battery
not shown
Real time clock - U178
Caution! The computer main board contains devices which can be damaged by static electricity
discharges. Use an anti-static wrist strap connected to the metal chassis of the computer
or touch one hand to the metal chassis before touching any component on the main board.
Notch indicates
device polarity