Sony UP-D70 Service Manual page 86

2. Cause and countermeasure
a) After power switch is turned ON, the indication is not appeared on the liquid crystal.
Does alarm turn on
and off when ribbon cassette
or paper feed tray is put
in and out?
YES
Check CN6 or IC107 on SY-270
Board, or LCD panel unit.
Does back light
of LCD light?
YES
Does TP113
on SY-270 Board
become H?
YES
Does clock
appear at TP114 on
SY-270 Board?
YES
Check peripheral of
IC101 on SY-270 Board.
(Check CPU.)
6-4
NO
Check CPU
operation on
SY-270 Board.
NO
NO
Check reset
signal.
Check peripheral of
IC111 on SY-270 Board.
(Check reset IC.)
NO
Check CPU
signal.
Check X101 on
SY-270 Board.
Is TP-1 on SY-270
Board 5 V?
(5 V system check)
YES
Check LCD panel unit or
harness.
When harness
from SY-270 to Power Supply is
disconnected, is through
1 3
of harness 5 V?
YES
Check short of 5 V
system in each board.
NO
NO
Check
Power Supply.
UP-D70/D70A (UC,CE)