Philips CD931 - Page 27

42
CHECK OF THE PHOTODIODES
signal Signal depends on Distance lens <>
IR LEO of remote control
T-23366A
CHECK OF LASER SUPPLY
The laser, the lasersupply plus the monitor diode form a feedback system.
A defect in the lasersupply may result in the destruction of the laser. If, in that case, the laser is replaced, (= complete
C.D.M.-unit) the new laser will also become defective. However, it is impossible to check and repair a feedback system if
a link is missing. For this reason the laser supply can be checked with teh replacement circuit for laser assembly.
8 Remarks
| O-O- | 1 8<V <2 3 REPLACEMENT CIRCUT FOR LASER ASSEMBLY
SK
| O07 frocmycaed a
After opening SK, the !ed will emit more light for a short moment.
to dL Aine teemect system seas to it chat the
tame amount of current
i
j
:
wa
when $8 open
The LEO eevte kite ght
T-23366B
CHECK OF CDM-9
WARNINGS
1, Never disconnect flex when power is on.
2. Laser power is adjusted during the production process
and may not be readjusted.
SPECIFICATIONS MEASUREMENT
cD
Signal Mode a
Bu2-L Test disc 3, play, total harmonic filter See
distorsion - output { technial
data
BU2-R Test disc 3, play, total harmonic 1 filter See
distorsion output | technial
data
Test disc 3, play signal-to-noise ratio filter
output
See drawing 30459A12
See drawing 30459A12
ie See drawing 30459A12
filter
output
Test disc 3, play signal-to-noise ratio See drawing 30459A12
T-23366M
Filter = 13th order filter 4822 395 30204
CO PLAYER
eg. SOUND TECHNOLOGY
ST 17008
30 689 AI2
PCS 60 109