Service manual

Video Processing
The sandcastle-pulse of the HIP will not be used for synchronization. The HOP will
generate synchronization signal derived from the feature box (PICNIC) signals. The HIP
itself (no external voltage) controls the Y/C switch in the HIP.
The Chrominance decoder in the HIP is full multi-standard, but only NTSC is decoded.
One crystal is connected to the pin 57 without any alignment. The crystal is also used
as a reference for the synchronization. A digital control circuit that is locked to the
reference signal of the color decoder determines the start-up of the sync. This crystal
may only be replaced by the original one. If just a crystal is taken, the internal
capacitance will be different and the effect will be that there is no color.
In the HIP, a sync separation circuit has been integrated. The HIP delivers the HA and
VA (50/60 Hz) to the PICNIC and PIP/DW module. On pin 59, there is the 1fH
sandcastle but this is not connected to any circuit and only used internally for the color
demodulator. The 2fH-sandcastle signal is generated by the HOP.
Video: Feature Box (PICNIC, diagram B3)
Introduction
The basic function of the Feature box (FBX6) is picture improvement, and depending on
the version several scan conversion methods can be applied. The PICNIC is the key
component.
In the N8-chassis, the feature box is integrated on the SSB. The PICNIC is used for the
60 Hz (prog. Scan) conversion. In the PICNIC, the following functions are present:
• The ADC.
• The DAC.
• The interlaced to progressive scan conversion.
• The noise limiter (DNR).
• The contrast improvement.
All these functions are integrated in one IC: SAA4978H, a 160 pin QFP.