Pcb Layout Of The Lcd Circuitry - Tait TM9100 Service Manual

2.
Tip
3.
4.
Figure 14.4

PCB layout of the LCD circuitry

top side
TM9100 Service Manual
© Tait Electronics Limited August 2005
Check the 3.3V supply voltage at pin 2 of the LCD connector J102.
J102 pin 2: 3.3V
If the signal is not correct, refer to
page 400.
For a quick check of the LCD without having to disassemble the
control head, connect a good LCD to the control head, or discon-
nect the LCD loom and connect it to a good control head.
Replace the LCD. Take care not to scratch the soft polarizer material
on the top side of the LCD.
Use an oscilloscope to check the signals of pins 3 to 7 of connector
J102.
J102 pins 3 to 7: The signals should be switching 0 to 3.3V in bursts of
0.125ms at approximately 1s intervals.
If any of the signals are missing or distorted, remove can E100 and
check for continuity between the FPGA and the LCD connector.
If necessary, replace the corresponding 100Ω resistor R4 to R8.
"Power Supply Faulty" on
Fault Finding of Control Head 403