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Check of Output signals for CVBS - Y / C.
VO
CVBS signals Testpoint 89
Video signal
1000 mVpp
White level
710 mVpp
Sync
290 mVpp
Burst
290 mVpp
VO-
::J
VO-
y
Y/C Sign. Testpoint 91/92
Video signal
White level
Sync
Chroma
1000 mVpp
710 mVpp
290 mVpp
300 mVpp
7.2.5
Multi Media Controller section
Required equipment:
Multimeter
Display terminal type
Digital
VT100 or equivalent
Digital oscilloscope
Analog oscilloscope
Timer/counter
7
.2.5.1
Supply voltages
Check if the following voltages
are present at connector 1001 :
pin 1,2,3 : + 5 V ± 5%
pin 4
: - 5 V ± 5%
pin 5
: + 25 V ± 5%
pin 6,7,8 : GROUND
7 .2.5.2
Clock signals:
Carry out measurements just after hardware reset.
This is done each time after pressing the OPEN/CLOSE
button or after power-on.
System clock
30.0000 MHz ± 1500 Hz (PAL)
30.2098 MHz ± 600 Hz (NTSC)
This system clock must be present
at
the following points:
IC7201 pin 30
IC7125 pin 115
At IC 7201 pin 29 Clock divided by two must be present :
15.0000 MHz (= 30.000 : 2 for PAL)
15.1049 MHz (NTSC)
At IC7201 pin 69 the UART clock of 68070 must be present :
Frequency4.9152 MHz± 250 Hz
At IC7206 pin 39 clock of '68HC05' must be present.
Frequency 4.000 MHz ± 100 Hz
At pin 127 of IC 7302 the DSP clock must be present:
Frequency 27.00 MHz± 100Hz
At pin 23 of IC 7320 the LEMM clock must be present:
Frequency 27 .00 MHz ± 1 OOHz
7.2.5.3 1
2
S
interface
FILTERN :
av
DMB
: Blockwave signal
CLAB
: frequency 2.8224 MHz (only for CD-DA)
WSAB
: frequency 44.1 kHz (only for CD-DA)
DEEM
: 0V (only for CD-DA and only if de-
emphasis track is played)
7 .2.5.4 Resat
circuitry
Press the OPEN/CLOSE button at front panel and measure
the 'RESETCD' time (low!). This 'low' time must be 140ms
± 20 ms. Also measure the RESETCD time (low!) if the
button is released. The signal RESETCD must be low for
140ms
±
20ms.
IC7201 pin 28 RESETN; low time = 250 ms ± 20 ms
7.2.5.5
Check of microprocessor
68070.
Check after power on:
IC7201, pin 27 (= HAL TN) = high (+ 5V)
IC7201, pin 28 (= RESETN) =high(+ 5V)
IC7201, pin 24 (= DTACKN) = changing high/low
IC7201, pin 26 (= BERRN) = high
(+
5V)
7.2.5.6 Low
level test
Purpose is to test the hardware with software.
Connect a terminal to the UART of microprocessor 68070
via connector at rear side port 2 (= BU-2).
Settings of the terminal:
Baudrate : 9600
start bit
: 1
data bists : B
stop bits
: 1
no parity/ no handshake
For the test sequence of the low level test see chapter 5. 1.
PCS 71 692
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