Oven Temperature Troubleshooting - Agilent Technologies 6890 Series Service Manual

Oven temperature troubleshooting

For each problem below, the probable causes and corrective actions are listed
in order of complexity/expense. The cheapest, most common, easiest to check
causes are listed first with the more complex, expensive causes following.
After identifying the problem, test for the probable causes in order from top
to bottom.
Problem
Oven does not heat.
Oven does not control
Oven temperature runs
away.
Oven temperature will not go
to maximum.
Jun 2001
Probable cause
Faulty fuse F1 or F2 on power
supply PCB.
Oven heater is open.
Faulty power supply PCB.
Faulty fuse F1 or F2 on main PCB.
Faulty main PCB.
Fast oven but GC configuration is
for regular oven.
Oven flap stuck.
Faulty main PCB.
Oven heater partially grounded.
Faulty main PCB.
Fast oven but power is 208 V rather
than 240 V.
Mainframe
Agilent 6890 Gas Chromatograph Service Manual
Oven and Temperature Control
Oven temperature troubleshooting
Corrective action
Check/replace both fuses.
Check resistance of oven heater.
Replace power supply PCB.
Check/replace both fuses.
Replace main PCB.
Check oven configuration.
Check oven flap.
Replace main PCB.
Ensure that the oven heater is not coming
in contact with the oven shell or other
nearby components.
Replace main PCB.
Correct power wiring in lab.
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