Pioneer RVD-XG10 Service Manual page 77

Gain and Bias Adjustment Methods
Gain and Bias
Adjustment Methods
In the dark room:
Requirements for a dark room for adjustment:
Connect a PC for servicing
Darker than approx. 10 lux
to the unit with an RS-232C
(The B. GAIN and B. BIAS adjustments
cable.
especially require darkness.)
Project a screen of approx.
40 inches and set the T-1
in the center.
Perform the ITO adjustment.
(The purpose of the ITO
adjustment here is to
achieve the gain and bias
adjustments properly.
After the gain and bias
adjustments, ITO adjustment
must be made again for daily
use.)
Output the 100% signal
(red) using the built-in
signal generator (SG).
While gradually increasing
the R. GAIN value, note the
value at which the illumi-
nance on the T-1 reaches
maximum. Then decrease
the gain value so that the
illuminance reaches 98%
of maximum.(Although the
same result may be
obtained by increasing the
gain value, be sure
to decrease it.)
Repeat the same
adjustment for G and B.
Display a lamp signal
using the built-in SG.
Check that the
No
displayed lamp signal
is smooth.
Yes
Check that the
white balance at a low
Yes
luminance and that at a high
luminance do not extraordinarily
differ from each other.
No
Perform the
ITO adjustment.
Finished.
Repeat the procedure from the beginning.If
adjustment fails again, a data jump in one of
2
the E PROMs can be suspected. If so, replace
both the main assy and the optical block.
When both the MAIN assy and the optical block
are replaced.
2
If other E PROMs are used on the MAIN assy
for maintenance, restore the original ones.
These adjustments are
essentially not required.
Adjust the bias values to
optimum with a lamp signal.
RVD-XG10, RVD-XG10ED, RVA-VK10
ITO Adjustment Methods
ITO Adjustment
Method
Output an R 30% signal
using the built-in signal
generator (SG).
Connect the T-1 and an
oscilloscope with a
dedicated cable.
Adjust R ITO to bring the
AC component to minimum.
Repeat the same
adjustment for G and B.
Finished.
77