Teledyne 7120 - NDIR analyzer - Manual (Page 75)

5 Maintenance Model 7120
5-8 Teledyne Analytical Instruments
5.8 TROUBLE SHOOTING CHART
SYMPTOM CORRECTIVE ACTION
A. Unit does not turn ON (a) Check AC voltage at inlet for
when actuating Power correct voltage. Reset breaker
Switch (Motor does not or switch to supply power to
turn). receptacle.
(b) Check power to terminal strip
located inside cabinet. CAUTION:
Terminal strip contains 90-220volt
line voltage which can be hazar-
dous. Check for loose connec-
tion to one of the terminal board
lugs; replace as required.
B. No Zero Control (with (a) Check that Power is ON and
unit on Zero gas). Out- chopper motor energized.
put is either dead or
fully saturated.
(b) Check that power supply voltages
are correct (+15VDC, Ä15VDC).
(c) Check output of TP6 on preamp
board with a DC voltmeter (should
be less than + or Ä 3VDC). If
output can be zeroed, check volt-
ages at TPl and TP2 on Linearizer
board (should also be zero). Then
check adjustments on E/I board.
(d) Check that infrared source is
operating. If cold, check
source element resistance and
connections.
(e) Check output of preamplifier