Varian ProStar 325 UV-Vis, Service Manual

Page: 119 / 149

ProStar325 Service Manual
Publication date 8 May 2003
119
7 Diagnostics
7.1 Introduction
Fault finding on the ProStar 325 detector is made simple by
several levels of diagnostic aids that are available to help
diagnose problems. This allows a CSR (Customer Service
Representative) to fault find the system to board level then verify
system operation from the host computer. Printed Wiring Board
(PWB) exchange is the recommended method of repair because of
the extensive use of surface mount devices on multi-layer boards.
The types of diagnostic tools available include;
•
Power on self-test (POST) routines which are executed
automatically when the instrument is switched on or reset
•
LED status indicators on the main PWB
•
Tests executed by firmware in conjunction with a 15-position
thumbwheel selector switch on the main PWB
•
A service diagnostics program (Diagnostics.exe)
7.2 Power On Self Test (POST)
Diagnostics switch position 0
These are performed when the detector is switched on during
normal operation. Position 0 is reserved for normal operation.
This allows for the normal start-up sequence (executed from the
boot block) to take place. Some tests include those used in the
thumbwheel switch selector diagnostic tests decribed (below).
Tests include:
*FLASH MEMORY CRC/ CHECKSUM BOOT BLOCK
Display a ’11’ on the LEDs or flash ’11’ if error.
*RAM test
Display a ’22’ on the LEDs or flash ’22’ if error.
*FLASH MEMORY test.
Display a ’33’ on the LEDs if the flash doesn’t respond or wrong
flash type
*ETHERNER CONTROLLER
If the Ethernet controller doesn’t repond or flash ’55’.
7.3 Power up sequence
Initializes all ports, interrupts, PCI bus
Test on-board SDRAM
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