Sony CNU-500 Installation And Maintenance Manual page 18

2-6. Self-Diagnosis
2. Confirm that the display shown in Fig. 3 appears and
set S3 switch (on the AT-100 board panel) to "0".
Turn S3 switch (on the AT-100 board panel) in the
order of 1, 2, 3, ... F and confirm that the display
shown in Fig. 4 appears.
Trouble 4 : S3 appears as an NG display or appears
as neither an OK nor NG display.
Remedy : Confirm if S3 or its peripheral block is
not defective.
AT-100 Main check mode. (AUTO)
EPROM Check OK
OPTION FLASH Check
WRITE
ERASE
READ
RAM Check OK
OPTION EEPROM Check
SWITCH Check
S2 OK
S3 F OK
S4 OFF
3. Confirm that the display shown in Fig. 4 appears.
Next, set S4 switch (on the AT-100 board panel)
sequentially to the UP and DOWN positions and
confirm that the display shown in Fig. 5 appears.
AT-100 Main check mode. (AUTO)
EPROM Check OK
OPTION FLASH Check
WRITE
ERASE
READ
RAM Check OK
OPTION EEPROM Check
SWITCH Check
S2 OK
S3 F OK
S4 DOWN OK
S5 OFF
Trouble 5 : S4 appears as an NG display or appears
as neither an OK nor NG display.
Remedy : Confirm if S4 or its peripheral block is
not defective.
2-6 (E)
Fig. 4
Fig. 5
4. Confirm that the display shown in Fig. 5 appears.
Next, set S5 switch (on the AT-100 board panel)
sequentially to the SET and CANCEL positions and
confirm that the display shown in Fig. 6 appears.
AT-100 Main check mode. (AUTO)
EPROM Check OK
OPTION FLASH Check
WRITE
ERASE
READ
RAM Check OK
OPTION EEPROM Check
SWITCH Check
S2 OK
S3 F OK
S4 DOWN OK
S5 CANCEL OK
Trouble 6 : S5 appears as an NG display or appears
as neither an OK nor NG display.
Remedy : Confirm if S5 or its peripheral block is
not defective.
c) Gen-lock Circuit Check
. Confirm that the display shown in Fig. 6 appears and
throw S5 switch (on the AT-100 board panel) to the
CANCEL position three times.
When an NTSC VBS or BB signal is input to the REFER-
ENCE connector;
The display below appears. (Fig. 7)
NTSC OK
PAL NG
When a PAL VBS or BB signal is input to the REFER-
ENCE connector;
The display below appears.
NTSC NG
PAL OK
N / P CHANGE Check
NTSC
OK
PAL
Fig. 6
CNU-500