Servicing Notes - Sony MDS-JE780 Service Manual

MDS-JE780
JIG FOR CHECKING BD BOARD WAVEFORM
The special jig (J-2501-196-A) is useful for checking the waveform of the BD board. The names of terminals and the checking items to be
performed are shown as follows.
GND : Ground
I+3V : For measuring Iop (Check the deterioration of the optical pick-up laser)
Iop : For measuring Iop (Check the deterioration of the optical pick-up laser)
TE : TRK error signal (Traverse adjustment)
VC : Reference level for checking the signal
RF : RF signal (Check jitter)
FE : Focus error signal
Iop TE VC
I+3V
GND
FE
RF
Iop DATA RECORDING AND DISPLAY WHEN OPTICAL PICK-UP IS REPLACED
The Iop value labeled on the optical pick-up can be recorded in the non-volatile memory. By recording the value, it will eliminate the need
to look at the value on the label of the optical pick-up. When replacing the optical pick-up, record the Iop value on the optical pick-up
according to the following procedure.
Record Procedure:
1. While pressing the l AMS L knob and x button, connect the power plug to the outlet, and release the l AMS L knob and
x button.
2. Rotate the l AMS L knob to display "[Service]", and press the YES button.
3. Rotate the l AMS L knob to display "Iop Write" (C05), and press the YES button.
4. The display becomes "Ref=@@@.@" (@ is an arbitrary number) and the numbers which can be changed will blink.
5. Input the Iop value written on the optical pick-up.
To select the number : Rotate the l AMS L knob.
: Press the l AMS L knob.
To select the digit
6. When the YES button is pressed, the display becomes "Measu=@@@.@" (@ is an arbitrary number).
7. As the adjustment results are recorded for the 6 value. Leave it as it is and press the YES button.
8. "Complete!" will be displayed momentarily. The value will be recorded in the non-volatile memory and the display will become "Iop
Write".
9. Press the REPEAT button to complete.
Display Procedure:
1. While pressing the l AMS L knob and x button, connect the power plug to the outlet, and release the l AMS L knob and
x button.
2. Rotate the l AMS L knob to display "[Service]", and press the YES button.
3. Rotate the l AMS L knob to display "Iop Read" (C26).
4. "@@.@/##.#" is displayed and the recorded contents are displayed.
@@.@ : indicates the Iop value labeled on the optical pick-up.
##.# : indicates the Iop value after adjustment
5. To end, press the l AMS L button or MENU/NO button to display "Iop Read". Then press the REPEAT button.
6
SECTION 1

SERVICING NOTES

CN105
I+3V
Iop
GND
TE
FE
VC
RF
1
I+3V
Iop
GND
for
TE
MDM-7S1A
FE
VC
RF
7