Philips CDR770 - Radial Servo

Service modes, repair tips and faultfinding trees
GB 26 CDR 3rd gen.5.
Figure 5-16
NOK
OK
OK
RADIAL SERVO OK
Switch on player
in MDD mode
SERVO DRIVERS CHECK
USE CDR MAIN BOARD CIRCUIT DIAGRAMS 1, 3 AND 4 AND CDR MAIN BOARD BOTTOM VIEW : SERVO DRIVERS TESTPOINTS
Execute "radial control" tests
Check power part
Check reset and clock part
Check S1V65 (=1V65) at
testpoint S9
NOK
Check IC7215, T7201, T7202
OK
Check MACE 7270
OK
VRA
GND
Check RAD+ signal at testpoint S14 :
+4V2 (going to 6V8 when executing "radial control on")
Check RAD- signal at testpoint S15 :
+0V65 (going to 4V3 when executing "radial control off")
NOK
OK
RADIAL SERVO OK
RADIAL SERVO
OK
Check
VRA signal at testpoint S13
Execute "radial control on" test
PM3392A
ch1:freq=532kHz
CH1:1.00 V= MTB 500ns
NOK
Check
VRA signal at testpoint S13
Execute "radial control off" test
PM3392A
ch1:freq=1.06MHz
CH1:1.00 V= MTB 500ns
VRA
GND
Check MACE 7270
NOK
Check driver 7240
Check MACE 7270
Check CDM3800
CL06532018_018.eps
290200