JVC UX-QD70S Service Manual page 45

(5) Iop check
In the MD test mode 1, when [ 0 ] key is pressed, the Iop display is performed by the following methods.
Purpose:
In order to check pick failure and static electricity failure by the laser ON current.
Measurement means:
"Laser ON current" mode was added to the static test mode. Laser current is measured in this mode.
Adjustment is not performed. Only a recording side corresponds.
AA : Laser power of playback in present (Current value mA)
BB : Laser power of recording in present (Current value mA)
CC : Laser power of playback in factory shipments (Current value mA)
DD : Laser power of recording in factory shipments (Current value mA)
Iop display (Only a recording side corresponds.)
The current of laser operation is measured and displayed.
Since change of the laser current of shipment and
the now can be seen, degradation of a pickup can be checked.
Adjustment is not performed.
* Pushing the [cancel] key of the remote controller,
it returns to the MD test mode.
It will display, if "DF, FF, AA, BB, CC, DD" are received from MD module.
@@@ : The amount of change is displayed by three figures. [ BB
(Below a decimal point is omission)
BB : Laser power of recording in present (Current value mA)
DD : Laser power of recording in factory shipments (Current value mA)
@@@ : The amount of change is displayed by three figures.
AA : Laser power of playback in present (Current value mA)
BB : Laser power of recording in present (Current value mA)
CC : Laser power of playback in factory shipments (Current value mA)
DD : Laser power of recording in factory shipments (Current value mA)
@@@ = The amount of change is displayed by three figures. [ BB
(Below a decimal point is omission)
Check the display of @@@ portion is 120% or less.
If a check is completed, pull out AC socket without pressing other keys..
MD is put in before a test.
(The data may be eliminated)
MD TEST MODE 1
Press the [0] key on the remote controller.
FL indication
IOP CHECK
FL indication
IO BB DD
@@@
display is finished.
DD x 100 ]
DD x 100 ]
It will display,
if "DF, FF, AA, BB, CC, DD" are
received from MD module.
(No.MB496)1-45