Tandy 102 Service Manual page 48

2. LCD doesn't function
2
No display at all
YES
NO
Check-the
source voltage (VDD, VEE, VB).
Refer to (1) "Doesn't work at all".
Check the RESET signal.
Refer to (6) "Reset doesn't function".
Check the LCD waveform.
(If abnormal, check the LCD power supply operation amplifier.)
Check the interface circuitry.
(Check all ICs connected to the bus line, M17 and M25.)
Check if the connector is correctly connected.
Check LCD drivers (on LCD PCB) HD44102 and HD44103.
(Or replace the LCD unit.)
END