Philips 13PT30L1 Service Manual page 61

E8 CHASSIS INTRODUCTION
The E8 series chassis is the Small Screen TV chassis produced by Philips Consumer Electronics Company
for the 1999-2000 model year. The E8 is used with 13, 19, and 20 inch CRT's. The E8 Tuning System
features a 181 channel Tuning System with On-Screen Display. The Tuning System uses two IC's mounted
on the main chassis. It consists of a Microcomputer IC and Memory IC. The Microcomputer communicates
with the Memory IC, the Customer Keyboard, the Remote Receiver, the U/V Tuner, the TV Signal Processor,
the Stereo Decoder (optional), and the Power On-Off circuitry. The Memory IC retains the settings for
favorite stations, customer control settings, feature settings, and factory setup data.
The chassis features a Very Large Scale Integration (VLSI) IC for TV Signal Processing. This IC performs
Video IF, Sound IF, AFT/AGC control, Horizontal Signal Processing, Vertical Signal Processing,
Horizontal/Vertical Synchronization, Chroma/Luminance Processing, and Video Switching between internal
and external inputs. On-Screen Graphics from the Microcomputer are placed on the main signal within the
TV Signal Processor. Automatic Volume Level (AVL) from the Microcomputer is sent to the TV Signal
Processor (Mono Sets) and to the Stereo Module (DBX Stereo Sets via the I 2 C bus). AVL for Normal Stereo
is switched by Pin 9 of the Microcomputer, 7600. The Mono version has a 1 watt audio amplifier. The
Normal Stereo version has a 2x1 watt amplifier. The DBX Stereo version has a 2x3 watt amplifier. Latin
American versions of this chassis may have a 2 or 3 watt Mono amplifier.
The E8 chassis features a Switching Mode Power Supply. A "HOT" ground reference is used in the primary
side of the power supply. "COLD" (signal) ground is used from the secondary of the power supply and
throughout the rest of the chassis. AN ISOLATION TRANSFORMER IS REQUIRED WHEN DOING
SERVICE ON ANY CHASSIS.