Chromatography Forum

Update: the mystery continues.
Astra Scientific checked our sideboard and it tunes fine on their machine.

So the sideboard isn't the reason there is no signal.
We have a new multiplier and filaments, so what else could it be?

So, is the new board working OK?

I had a problem with no current that I just could not solve and finally sent the whole 5973MS off to Dennis Vogul at Full Spectrum and as it turned out... At first they could not figure it out either but an old hand mentioned a problem that had happened in the past. They had a bad batch of filaments come through that sagged just enough on heating so that they shorted against the source body. They gave me new filaments and it worked fine after that.

As a learning exercise, what were the MS symptoms that made a sideboard repair necessary ?

Sorry so late on this one.

First major error is when it returns "Can not achieve constant peak width" or other peak width errors when tuning. Also if you check the tune and ever few days your peaks in manual tune are getting much wider or narrower. This is a problem in the Mass Filter usually associated with components inside the metal box in the middle of the board.

Filaments not coming on can be a problem with circuits in the front of the board where it connects to the pass through for filament and source connections.

Little or no signal could be the Logamp which is the red box in the back end of the board.

Thank-you James

My experience is that the sideboard is not usually the problem...

More likely : a combination of bad filaments, ceramic source board, damaged source wires, quad contacts and conductive fibres inside the HED/EM horn assembly have been my observation going back to the days of the 5971.

Hi.. I need some help.. We have an issue in CID gas controller (I think so). The CID pressure is not present and the diagnosis (API and HV) shows constant 3.3 volts for both "CID on" and "CID off" positions. This voltages were present even after dismountung the efc connector.

Instrument model: Varian 450GC-300MS

Software type: MSWS v. 7.0

The CID Gas Controller in the Variant 450GC-300MS instrument is exhibiting a persistent issue where both the "CID on" and "CID off" positions display a constant 3.3-volt reading, even after disconnecting the EFC connector. This problem requires further troubleshooting and diagnosis to determine the root cause and potential solutions. Please refer to the instrument's manual or seek assistance from Varian support.