JVC 250 Service Manual page 93

Chapter 5---Electronics
Figure 5-24 Scan Reversal PCB I/O Diagram for CRT Yokes.
Scan Reversal PCB - Operation
The Scan Reversal PCB has several functions. It provides an interface for scan
reversal, and provides for horizontal width adjustment. The Scan Reversal PCB
outputs the convergence and deflection waveforms that drive the CRT
convergence and deflection yokes, and it contributes significantly to the CRT
Protection circuit.
The Scan Reversal PCB provides an interface for reversing the projection mode
from front to rear projection and from upright to inverted (upside down) mounting
projection setups. The projection modes are changed by switching a jumper from
one connector to another on the Scan Reversal PCB. J100 and J101 are for
horizontal scan connections. J53 and J53A are the vertical scan connections, and
J50 and J50A are convergence jumper connections. The Model 250 comes set for
5-38 Model 250 Service Manual