Video Processor Board P/N 104672 (Vpb) - JVC 330 Service Manual

Video Processor Board P/N 104672 (VPB)

The Video Processor Board (VPB) plugs into the electronics card cage.
It is the rear-most card in the card cage. The VPB is the only card in the card cage
that is held in by fasteners. There are four screws that tie the input tray to the rear
panel of the card cage. The input tray is an aluminum panel that attaches to the
VPB input BNC connectors. The input tray is a separate assembly and is not
included with the VPB when a new or repaired board is shipped.
The following functions are provided by the VPB:
The block diagram (Figure 2-15) description, along with the I/O description in the
following section, provide information to perform module-level troubleshooting.
Model 330, 340SC and 370SC Service Manual
Image and sync signal input.
Image and sync signal multiplexing.
Sync signal stripping.
Brightness and contrast control.
CRT protection logic.
Internal and external display multiplexing.
Image signal gamma correction.
LCLV uniformity correction.
LCLV bias.
Dynamic focus signal modification.
Chapter 2—Functional Description
2-43