Chapter 4 -- Control Circuitry - Mitsubishi Electric HITACHI VS-50111 Troubleshooting Manual

From the above Block Diagram it is apparent that the
Control Circuitry in the V20 chassis is not radically dif-
ferent from other chassis types.
1) The heart of the circuitry is a µPC IC.
2) Two EEPROM(s) are used to store user
programming and service alignment data. (Plus,
another EEPROM is used in the Convergence
Circuitry to total three.)
3) User commands originate from front panel or
remote control.
4) Status Inputs keep the µPC aware of current
operating conditions.
5) µPC output commands control the TV's
circuitry.
Chapter 4
Control Circuitry
4-1
V20 Chassis Technical Training
Basic Operating Requirements
The µPC basic operating requirements have not changed:
• DC supply
• Ground returns for the internal circuitry
• Clock Signal(s) for timing
• Method of resetting the µPC
Figure 1 illustrates the basic µPC requirement cir-
cuitry in the V20 chassis. The 5VS supply furnishes
DC power at pins 16, 62 and 99 of the µPC. Ground
returns for the internal circuitry are provided by the
ground connections at pins 9, 14, 64 and 96.
and Troubleshooting Guide