Service Hints - Philips FWM589 Service Manual

Service Hints

In case of symptom „skipping tracks" perform
following actions:
1. VERIFY THE COMPLAINT
PLAYABILITY CHECK
Use CDDA SBC 444A: . . . . . . . . . . . . . .4822 397 30245
TR 14 (600µ black dot) maximum at 01:15
TR 19 (fingerprint)
TR 10 (1000µ wedge)
Use CD-RW Printed Audio Disk . . . . . . .7104 099 96611
TR 3 (Fingerprint)
TR 8 (600µ black dot) maximum at 01:00
• playback of all these tracks without audible disturbance
• jump forward/backward within a reasonable time
2. CLEAN THE LENS
CD DRIVE – LENS CLEANING
Before touching the lens it is advised to clean
the surface of the lens by blowing clean air over
it in order to avoid that little particles make
scratches on the lens.
Because the material of the lens is synthetic and coated
with a special anti-reflectivity layer, cleaning must be
done with a non-aggressive cleaning fluid. It is advised to
use "KODAK LENS CLEANER CAT 176 71 36", available
in normal photo shops.
The actuator is a very precise mechanical component
and may not be damaged in order to guarantee its full
function. It is advised to clean the lens gently (don't press
too hard) with a soft and clean cotton bud moistened with
the special lens cleaner.
The direction of cleaning must be in the way as indicated
in the picture below.
10-2
3. MEASURE THE EYE-PATTERN SIGNAL
EYE-PATTERN SIGNAL – JITTER MEASUREMENT
Measure the signal direct on resistor 3898 using an
oscilloscope (see also chapter 10-9).
EYE-PATTERN
TB = 0.5µs/div
HF-Amplifier
+5V_HF
2,4V
7876
2883
BC847B
3901
470n
1,8V
Σ (A-D)
560R
1,2V
2881
560p
See below examples of the signal. Amplitude should read at
least 700mVpp using SBC444A.
If the oscilloscope shows a signal like the 'bad' one, and/or
the amplitude decreases within 1minute - the CD drive has
to be replaced.
D3
D2
800mVpp
D1
3893
VrefCD10
470R
3895
27K
3896
+3.3V
100R
2813 3898
HFIN
4n7 220R
3903 3904
3K3 3K3
LD
ON
470R
to 3826,3827
3899
3906
2,6V
CD_DA: 0V / CD_RW: 3V
2K7
0,65V
7878
+3.3V
BC847B
7877
BC847B
good
bad
11
D4
10 D3
9 D2
8
D1
VREF GE
7 VRIN
6
IREF
5
VDDA1
4
VSSA1
3
ISLICE
2
HFIN
1
HFREF
LD
ON
64
3923
10K
Sanyo
DA12T3
Drive detection