Portable Oxygen Monitor
Service Manual
Teledyne
Analytical
Instruments
41
50
5
The ADC circuit failed during POST.
6 (5)
6
(There is no
indication of
which key is
stuck)
A stuck key has been detected. The second digit
example (5) on the display shows which key is
stuck:
0 - Low Alarm
1 - Batt
2 - Cal
3 - Up
4 - Down
5 - Silence
6 - High Alarm
7 - Alarm Test
8 - Key Lock
7(2) 7
(There is no
indication of
the type of
DAC failure)
A failure has occurred during the automatic
calibration of the digital to analog converter (DAC)
circuit. The second digit example (2) shows the
type of digital to analog failure.
0 - Measurement
1 - High Test
2 - Low Test
3 - Offset Cal
4 - Gain Cal
3.10 Other Problems with the Instrument
Most other problems arise from either mechanical damage from the
instrument falling from a bench or table, or electronic component
failure. In these units, repair or troubleshooting the PCB or individual
component on the board is not feasible. It requires specialized test
equipment and probes not generally available to the public. Under most
circumstances a replacement of the entire PC Board is recommended.
The instrument must be returned to the factory for PCB installation.
Occasionally, depending on the environment of use, keys can
become stuck or function erratically due to contamination. Use a mild
