RWB II PLUS MICROPROCESSOR CONTROL
MAINTENANCE
S70-200 OM
Page 25
EPROM MEMORY I/C CHIP REPLACEMENT
Microprocessor EPROM memory I/C chips are located in-
side the microprocessor console on the SBC board. A spe-
cial tool is required to remove these chips to lessen the
chance of damaging them (See Troubleshooting The
Microprocessor). The procedure to replace EPROM memory
chips is outlined below:
1. Shut off control power.
2. Remove the microprocessor console cover.
3. Using a chip extraction tool, remove the old EPROM chips
from the SBC board. Pay particular attention to the orienta-
tion of the notch on the end of the chip; then install new chip
with the notch in the same position. NOTE: The chip la-
beled 4 must be inserted into socket U4 and the chip
labeled 5 must be inserted into socket U5.
SBC BOARD REPLACEMENT
The procedure to replace SBC boards is outlined below:
1. Shut off control power.
2. Remove the old board from the machine and the new
board from its packing and place both on an antistatic sur-
face.
3. Remove the program chip(s) from the defective board and
install them in the replacement board.
Pay particular attention to the ori-
entation of the notch(es) on the end
of the chip(s). Install the chip(s) on
the replacement board in exactly the same position as
they were on the defective board.
4. IMPORTANT: Before installing the new board, determine
if there are gray/yellow wires from P15 (see the SBC wiring
diagram for location) on the old board. If they are present,
the display is the old style and the new board can be in-
stalled without modification.
5. If the gray/yellow wires are not present on the old SBC,
the machine is equipped with a new style display. Resistor
R6 must be removed from the new board by cutting the wire
leads on either side of the resistor.
6. Then install the modified replacement board in the panel.
MICROPROCESSOR DISPLAY REPLACE-
MENT
The procedure to replace the microprocessor display is out-
lined below:
1. Shut off control power.
2. Remove the defective display(s).
3. Install the new display(s).
4. If present, remove the grey/yellow wires from P15 (see
the SBC wiring diagram for location) to the display(s) as
they are no longer needed.
5. If resistor R6 is present on the SBC, cut off the wire leads
on both sides (see the SBC wiring diagram for location) and
remove it. This resistor is no longer needed.
OUTPUT FUSE REPLACEMENT
1. Shut off control power.
2. Remove the microprocessor console cover.
3. Identify the faulty fuse.
4. Use a voltmeter to verify that no voltage is present on
either side of the fuse.
5. Remove the faulty fuse using a fuse puller or screwdriver.
6. Install a new plug-type fuse.
To Next Page
Loading...
