Marantz DR2100, Service Manual

Page: 21 / 53

21
8.1.2 Test instructions
Clock signal
As clock driver for the display controller, a resonator of 8 MHz
(XY01) is used. The signal can be measured at pins 8 and 9 of
the display controller : 8 MHz
±
5% .
I2C DATA/I2C CLK
These lines connect to the DASP master processor via
respectively pin 5 and pin 7 of conn. JU02. When there is no
communication, they should have the high level (+5V). The
oscillogram below gives an indication of how these signals
should look like.
Figure 8-2 ‘I2C signals’
CH1! 2. 00 V =
CH2 2 V= M TB10.0m s
ch 1+
+5V
0V
+5V
0V
I2C DATA
I2C CLK
CL 96532076_025.eps
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0V
+5V
-35V
IR receiver - remote control
In the DR2100 the IR receiver RPM6934 (ZY83, ZY84) is
mounted on the display board. In all versions the IR receiver
connects to the display controller. The signal coming from the
receiver can be checked at pin 3 of conn. JU05. This signal is
normally high (+5V). When the remote control is being
operated, pulses mixed in with the +5V can be measured. The
oscillogram gives an indication of how the signal looks like with
the RC being operated.
Figure 8-3 ‘IR receiver signal’
CH1! 2.00 V= MTB20. 0ms ch 1+
1
+5V
0V
CL 96532076_021.eps
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