Multiplex MB-8-1, Technician'S Handbook

Page: 132 / 178

132 Part Number STH034 3/12
LCD TOUCHSCREEN & CONTROL BOARD
Function
Touch screen is the user interface with the machine
and sends input to the control board.
Control board monitors inputs and sends signals to the
relay board to energize and de-energize components.
Specifications
The LCD touchscreen display and control board work
in tandem to provide user interface and control
component operation.
Check Procedure
1. Reboot machine by moving toggle switch off/on or
disconnecting and reconnecting main power
supply.
Refer to appropriate flowchart for the problem you are
encountering. Touch screen and control board
diagnostics are covered by a process of elimination in
the troubleshooting and component check procedures
unless the LCD screen is entirely black (no power) or
entirely white (powered).
1. Touch screen is black
A. Verify processor board has energized lights -
Refer to “Control System” on page 97
B. Verify touchscreen power connector is
connected to control board.
Touch screen is white
A. Verify connections are secure by removing
and reinserting connectors.
B. Replace touchscreen