Chromatography Forum

Hi,

I have just attempted restarting an HP GC-MS system after it sat for a number of months unused. I first got weird results on the foreline pressure, with readings > 4000 despite the backing pump working fine. On checking MS status, I got the following message:

"HC11 Fault.
Heater Timeout. Must power cycle to clear.
Heater Voltage too LOW.
No Heater Voltage Present.
Quad RTD is Shorted.
Quad RTD not connected.
Source RTD is Shorted.
Source RTD not connected."

Any ideas what might be causing this? What is the RTD? I can't find reference to it in the manual.

Thanks for any help.

Andrew

Are all the source connections made correctly?

RTD is the temperature monitoring theromcouples(or diodes) inside the analyzer, one for source, one for quads.

The errors are showing that you are not getting power to the heaters inside the analyzer and no signal from the temp sensors.

You could have a problem as simple as the two cables not connected to the analyzer door near the front, cables not connected on the inside, or as complex as a circuit board that has failed. First check that all of the connectors have cables going to them on the outside of the analyzer door. If those are connected then vent and open it up and make sure the white and green wires at the bottom of the circuit board just inside the analyzer vacuum chamber are connected.

There is also a vacuum sensor tube located where the rough pump tubing leaves the high vacuum pump under the analyzer, should have a blue connector attached to the stainless steel vacuum sensor, if that is not connected it will think the vacuum is not working, which will prevent everything else from powering up. Also make sure the vent valve is closed, possibly put a little high vacuum grease (Apezion L is best) on the oring behind the vent knob. Also the oring around the vacuum chamber can get lint on it and prevent it from sealing completely, a light film of grease on it can help the seal, just add some then wipe it clean, only need a film that is barely there to make it seal.