Denon DCD-A100, Service Manual

Page: 9 / 127

9
DIAGNOSTICS OF OPTICAL PICKUP AND REPLACING TRAVERSE UNIT
Make failure diagnostics of the Optical Pickup as follows.
If the laser drive current (IOP) becomes more than 1.5 times of the initial value, the Optical Pickup should be replaced.
The laser drive current initial value is checked by "IOP checked Method" of next page.
In case of replacing the Pickup, change the whole part of the Traverse Unit.
No mechanical adjustment is necessary after the replacement.
Laser drive current initial value:
FL Display (The display part of 13 digits)
DVD :
(SACD)
1 2 3 4 5 6 7 8 9 10 11 12 13
- - - T 2 3 - m m m m - -
FL Display (The display part of 13 digits)
CD :
1 2 3 4 5 6 7 8 9 10 11 12 13
- - - T 2 1 - m m m m - -
FL Display (The display part of 13 digits)
DVD :
1 2 3 4 5 6 7 8 9 10 11 12 13
- - - T 6 D
±
m m . m - -
1. IOP checked Method
Select the laser ON/OFF(CD/DVD)mode of the test mode, and check the IOP value of DVD(SACD) laser or CD laser.
1.1 DVD(SACD) laser current check
(1) Press the
8
or
9
button to display the laser current value, and then select “T24”.
(2) Check the current value of IOP (nnnn)
FL Display (The display part of 13 digits)
1 2 3 4 5 6 7 8 9 10 11 12 13
- - - T 2 4 - n n n n - -
(
-
: Off, DVD(SACD) laser, Initial value: Current value: nn.nn [mA])
1.2 CD laser current check
(1) Press the
8
or
9
button to display the laser current value, and then select “T22”.
(2) Check the current value of IOP (nnnn)
FL Display (The display part of 13 digits)
1 2 3 4 5 6 7 8 9 10 11 12 13
- - - T 2 2 - n n n n - -
(
-
: Off, CD laser, Initial value: Current value: nn.nn [mA])
DVD: over ±15 %
FE balance value check
Mecha Unit replacing
Disc no read, unsteady playback, etc.
Laser drive current (Iop) check
HF wave form check
(Refer to WAVE FORMS)
Mecha Unit replacing
Laser current (Iop) memorizing after re-
placement
Present value exceeds
the initial value by 1.5
times
Disc no read, unsteady playback, etc.
s