Virginia Controls, LLC
MH-3000 User Manual, 1_03C10-VC
Page 109
7.
Remove the CPU board.
8.
Install the new CPU board in the reverse order.
9.
If the new CPU was not provided with an EPROM Program Chip, then carefully remove
the chip from the old CPU and install it in the new CPU as described under EPROM
Memory Chip Exchange below.
10.2.2
EPROM Memory Chip Exchange
WARNING: IF YOU NEED TO CHANGE THE EPROM PROGRAM CHIP ON
THE CPU BOARD, MAKE SURE YOU READ THE INSTRUCTIONS AND
KNOW EXACTLY HOW TO INSTALL THE NEW CHIP. PLUGGING THE
EPROM IN UPSIDE-DOWN MAY DAMAGE YOUR CHIP. STATIC
ELECTRICITY CAN DAMAGE THE EPROM, SO AVOID TOUCHING THE
PINS ON THE CHIP, AND GROUND YOURSELF (BY TOUCHING THE
CONTROLLER CABINET) BEFORE TOUCHING THE CHIP OR THE
CONTROLLER. DO NOT EXPOSE THE EPROM PROGRAM CHIP TO
BRIGHT LIGHT, AND DO NOT REMOVE THE LABEL OVER THE EPROM
PROGRAM CHIP WINDOW.
To exchange the EPROM memory chip on the CPU board:
1.
Turn off power to the controller.
2.
Using a small screwdriver, or other appropriate tool, pry out the old EPROM chip by
inserting the screwdriver between the chip and its socket from the right side. Gradually
work the chip out, trying to avoid swinging it out, which would bend the pins at one end,
but rather prying it straight out by working the screwdriver under the chip.
3.
Insert the new EPROM chip by orienting it properly, so that the notch is at the left, to
match the socket, and all the pins line up with the socket. LEAVE TWO EMPTY HOLES AT
THE LEFT END OF THE CHIP (the end next to the notch). It should not be necessary to
use force to insert the EPROM chip, but apply slight sideways pressure to line up the
rows of pins with the holes in the socket, if necessary, then evenly press the EPROM chip
into place.
4.
Do not apply power until the orientation of the chip has been checked. Also verify that
ALL pins are properly in the socket, and that none of them have been bent out of place.
10.2.3
Input/Output Board Exchange
To exchange on I/O board:
1.
Change the Address Switches on the new I/O board to match the board it will replace.
2.
Turn off the power to the controller.
EPROM Chip Positioning
Notch
