Sony CNU-500 Installation And Maintenance Manual page 19

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 7 : The signal input to the REFERENCE
connector appears as an NG display or
the NG display stops halfway.
Remedy : Confirm that IC42 or its peripheral block
(area enclosed with A-13, I-15, G-13, and
G-15 on AT-100 printed circuit board),
and CN1 harness are not defective.
d) Command Block Check
1. Confirm that the display shown in Fig. 7 appears and
set S5 switch (on the AT-100 board panel) to the SET
position. Release S5 switch (on the AT-100 board
panel) just when the display shown in Fig. 8 appears.
Confirm that an OK message is displayed at the point
where a CCA-5 cable is connected and that an NG
message is displayed at the point where it is not
connected.
AT-100 Com. check mode.
MSU RCP1 OK
CCU1 RCP2 NG
CCU2 RCP3 NG
CCU3 RCP4 NG
CCU4 RCP5 NG
CCU5 RCP6 NG
CCU6 VCS NG
CNU-500
N / P CHANGE Check
NTSC OK
PAL
NG
Check end Push [SET]key
Fig. 7
(AUTO)
Push [SET] key !!
Fig. 8
Trouble 8 : An NG message is displayed at the point
where a CCA-5 cable is connected.
: The MSU ↔ RCP1 display is NG.
Remedy
→ Confirm if IC902 and its peripheral
block, and IC305 and its peripheral
block are not defective.
The CCU1 ↔ RCP2 display is NG.
→ Confirm if IC304 and its peripheral
block, and IC405 and its peripheral
block are not defective.
The CCU2 ↔ RCP3 display is NG.
→ Confirm if IC404 and its peripheral
block, and IC505 and its peripheral
block are not defective.
The CCU3 ↔ RCP4 display is NG.
→ Confirm if IC504 and its peripheral
block, and IC605 and its peripheral
block are not defective.
The CCU4 ↔ RCP5 display is NG.
→ Confirm if IC604 and its peripheral
block, and IC705 and its peripheral
block are not defective.
The CCU5 ↔ RCP6 display is NG.
→ Confirm if IC704 and its peripheral
block, and IC805 and its peripheral
block are not defective.
The CCU6 ↔ VCS display is NG.
→ Confirm if IC804 and its peripheral
block, and IC903 and its peripheral
block are not defective.
2-6. Self-Diagnosis
2-7 (E)