Marantz MAR770 - Manual (Page 21)

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8.1.3 Display board troubleshooting guide
Figure 8-9 Display board troubleshooting’
SWITCH POWER ON,
EXIT STAND BY
MODE
DISPLAY BOARD
OK
DISPLAY?
CHECK :
SUPPLY VOLTAGES
-35V ± 5 % at conn. JY01-2
3V8 ± 10% bet ween conn. JY01-1 and JY01-3
+5V ± 5 % at conn. JY01-10
CLOCK SIGNAL
8Mhz at pins 8, 9 of QY01
CONTROL SIGNALS
RESETN 3V3 (high) at conn. JY01-4 after start up
I2C DATA at conn. JY01-5
I2C CLK at conn. JY01-7
FTD DRIVE LINES
Filament voltage 3V8 10% between pins 1-3 and
pins 1-52 of the FTD (VX01)
Grid lines (see test instructions)
Segment lines (see test instructions)
ELECTRICAL SERVICE DIAGNOSTICS - Local display test
YES
YES
YES
KEY
FUNCTIONS?
REMOTE
CONTROL?
NO
NO
CHECK:
KEY MATRIX LINES (see test instructions)
ELECTRICAL SERVICE DIAGNOSTICS – Keyboard test
EASY JOG KNOB (see test instructions)
NO CHECK:
IR RECEIVER signal at pin 22 of QY01 ( see test instructions)
ELECTRICAL SERVICE DIAGNOSTICS – Remote control test
CL 96532076_020.eps
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