Mindray Passport 5-Lead, Service Manual

Page: 203 / 544

Passport 5-Lead, 5L, LT, XG Service Manual 0070-00-0420 2 - 1
2.0
Theory of Operation
Contents of this Chapter ............................................................. Page
Block Diagrams .......................................................................... 2-1
Detailed Circuit Descriptions........................................................ 2-7
The Theory of Operation provides block diagrams, an overview of each board, and a
detailed circuit description of each board. The circuit descriptions are included to assist
service personnel while repairing the printed circuit board on a component level. Refer to the
schematic diagrams in Chapter 2 when reading the Detailed Circuit Descriptions.
2.1 Block Diagrams
The Block Diagrams indicate the internal organization of the instrument. It depicts several
circuit boards, numerous connectors and the cathode ray tube. The block diagrams are used
to gain both familiarity with the instrument and locate malfunctioning PC boards as readily as
possible. To avoid clutter, the number of PC board interconnects is minimized. The
interconnects shown represent major or essential signal flow and clock connections. Also, the
power supply connections for each board are shown.
OVERALL BLOCK DIAGRAMS ....................................................... Page
Passport 5L/LT Block Diagram .................................................... 2-3
Passport 5L with CO
2
Block Diagram .......................................... 2-4
Passport XG Block Diagram........................................................ 2-5
Password XG, (Masimo) Block Diagram...................................... 2-6
DETAILED BLOCK DIAGRAMS ....................................................... Page
Interconnect Board ..................................................................... 2-8
Overall Front End Block Diagram ................................................ 2-14
ECG Pre-Amp Block Diagram ...................................................... 2-14