The Diagnostic Signal I/O Function; Status Leds; Cpu Status Indicator; Figure 5-11. Cpu Status Indicator - Teledyne T400 User Manual

5.7.3 T D
HE IAGNOSTIC
The Utilities>Diagnostics menu provides a view of the digital and analog I/O signals in
the analyzer. These signals, combined with a thorough understanding of the instrument's
Theory of Operation (found in Section 6), are useful for troubleshooting in three ways:
• The technician can view the raw, unprocessed signal level of the analyzer's critical
• Many of the components and functions that are normally under algorithmic control of
• The technician can directly control the signal level Analog and Digital Output signals.
This allows the technician to observe systematically the effect of directly controlling
these signals on the operation of the analyzer. Use the Utilities>Diagnostics menu to
view the raw voltage of an input signal or the Setup menu to control the state of an output
voltage or control signal.
5.7.4 S
TATUS
Several color-coded light-emitting diodes (LEDs) are located inside the instrument to
assist in determining if the analyzer's CPU, I
properly.

5.7.4.1 CPU STATUS INDICATOR

DS5, a red LED that is located on the upper portion of the motherboard, just to the right
of the CPU board, flashes when the CPU is running the main program loop. After power-
up, approximately 30 to 60 seconds, DS5 should flash on and off. If the front panel
display is working, but DS5 does not flash, then the program files have become
corrupted. If after 30 – 60 seconds neither the DS5 is flashing nor is the front panel
display working, then the CPU is bad and must be replaced.
118
S I/O F
IGNAL
inputs and outputs.
the CPU can be manually exercised.
LED
S
Motherboard

Figure 5-11. CPU Status Indicator

Teledyne API – Model T400 O
UNCTION
C bus and relay board are functioning
2
CPU Status LED
Analyzer
3
083730400A DCN8130