Teledyne T100, Instruction Manual, Page: 267 / 404

Teledyne ML - T100 UV Fluorescence SO2 Analyzer Troubleshooting & Repair
06807A(DCNxxxx) 267
10.2. STATUS LEDS
Several color-coded, light-emitting diodes (LEDs) are located inside the instrument to
determine if the analyzer’s CPU, I
2
C communications bus and relay board are functioning
properly.
10.2.1. MOTHERBOARD STATUS INDICATOR (WATCHDOG)
DS5, a red LED on the upper portion of the motherboard, just to the right of the CPU
board, flashes when the CPU is running the main program. After power-up, DS5 should
flash on and off about once per second. If characters are written to the front panel display
but DS5 does not flash then the program files have become corrupted. Contact Teledyne
ML’s Customer Service department.
If DS5 is not flashing 30 - 60 seconds after a restart and no characters have been written
to the front panel display, the firmware may be corrupted or the CPU may be defective. If
DS5 is permanently off or permanently on, the CPU board is likely locked up and should
the analyzer not respond (either with locked-up or dark front panel), then replace the
CPU.
Mother Board
CPU Status LED
Figure 10-3: CPU Status Indicator
10.2.2. CPU STATUS INDICATORS
The LEDs on the CPU card (Figure 9-14) are described as follows:
Power LED Red normally lit
IDE LED Green lit when active (read or write)