Sony UP-D70XR, Service Manual

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6-4
UP-D70XR
2. Cause and countermeasure
a) After power switch is turned ON, the indication is not appeared on the liquid crystal.
When harness
from SY-270 to Power Supply is
disconnected, is
1
through
3
of harness 5 V?
Does alarm turn on
and off when ribbon cassette
or paper feed tray is put
in and out?
NO
YES
YES
Does back light
of LCD light?
NO
Check peripheral of
IC101 on SY-270 Board.
YES
Is TP-1 on SY-270
Board 5 V?
NO
Check short of 5 V
system in each board.
YES
NO
Check
Power Supply.
Check CN6 or IC107 on SY-270
Board, or LCD panel unit.
Does TP113
on SY-270 Board
become H?
Does clock
appear at TP114 on
SY-270 Board?
YES
YES
Check LCD panel unit or
harness.
NO
Check peripheral of
IC111 on SY-270 Board.
(Check reset IC.)
NO
Check X101 on
SY-270 Board.
(Check CPU.)
(5 V system check)
Check CPU
operation on
SY-270 Board.
Check reset
signal.
Check CPU
signal.