Service manual

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8.1.3 Display board troubleshooting guide
Figure 8-4 Display board troubleshooting’
SWITCH POWER ON,
EXIT STAND BY
MODE
FRONT, MAIN u-COM BOARD
OK
DISPLAY?
CHECK :
SUPPLY VOLTAGES
+5V
5 % at conn. JU04-1
CLOCK SIGNAL
8Mhz at pins 82, 83 of QU01
CONTROL SIGNALS
RESET IN 3V3 (high) at conn. JU02-4 after start up
I2C DATA at conn. JY01-5
I2C CLK at conn. JY01-7
ELECTRICAL SERVICE DIAGNOSTICS - Local display test
YES
YES
YES
KEY
FUNCTIONS?
REMOTE
CONTROL?
NO
NO
CHECK:
KEY LINES
ELECTRICAL SERVICE DIAGNOSTICS – Keyboard test
EASY JOG KNOB
NO
CHECK:
IR RECEIVER signal at pin 63 of QU01
ELECTRICAL SERVICE DIAGNOSTICS – Remote control test
CL 96532076_020.eps
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