Mitsubishi Electric HITACHI VS-50111 Troubleshooting Manual page 35

Although all signals are directed to the DOUBLER cir-
cuitry, they may not be processed by that circuitry. When
the main picture source is either 480p or 1080i, and the
selected display format is Standard, the signals do not
require DOUBLER signal processing. The signals are
selected by the PIP switch circuitry and are applied di-
rectly to the VCJ, bypassing the DOUBLER circuitry.
If PIP is activated, the sub picture is processed by
the DOUBLER circuitry and then inserted in the main
picture in the PIP Switch circuit.
If another display format is selected, or a POP function
is activated, the shape of the main picture has to be
changed. To do this the main picture signal must be
processed by the DOUBLER circuitry. Then any POP/
PIP insertion occurs in the DOUBLER circuitry and that
signal is selected by the PIP Switch and applied to the
VCJ.
The circuitry in the VCJ converts the YCbCr signals
to the RGB format and directs them to the CRT's
RGB amplifier circuitry.
A/V SW & 3DYC Circuitry
Figure 1 illustrates the A/V SW and 3DYC circuitry.
The A/V SW circuitry selects NTSC format signal
sources, from one of the Tuners or an External Video
Input. This circuitry is less complicated than previous
models, since only one IC is used, IC2K00.
5-3
V20 Chassis Technical Training
and Troubleshooting Guide