GSi TYMPSTAR 1, Service Manual

Page: 186 / 224

Chapter 7
A block diagram of the TympStar is shown on the following pages. The block
diagram and block diagram description outlined below are only intended to assist in
the recognition and assembly-level troubleshooting of major assemblies. Compo-
nent-level troubleshooting and parts replacement should only be performed by GSI
service technicians at the factory.
The TympStar is comprised of the following 9 major assemblies:
· LCD
· Printer
· Probe
· Pump
· Digital board
· PC104 board
· Analog board
· Power supply board
· Printer board
The LCD assembly is comprised of the following:
· The liquid crystal display
· Controller circuitry
· Backlight inverter board
The printer is comprised of the following:
· Paper advance motor
· Paper “present” photo eye
· Fixed thermal head
The probe is comprised of the following:
· Two speakers, an IPSI stimulus speaker and a probe tone speaker
· One microphone assembly for measuring the reflected probe tone signals
· One pressure transducer assembly for monitoring the pneumatic system pressure
· One flash ROM for storage of probe related calibration data
The pump is comprised of the following:
· A stepper motor with a linear shaft driven by a “worm gear”
· A bellows assembly attached to the motor shaft for generation of positive and
negative pressures
· A positive and a negative over-pressure sensor switch which prevent excessive
pressures
· Vent and hold valves
Grason-Stadler
Block diagram
description of assem-
blies
LCD assembly
Printer
Probe
Pump
7 - 6