Chromatography Forum

I vented the system last week and cleaned the source, during pump down the temperature (actual) reading for the source heater was bouncing around between 170-500 degrees (set at 230) and the quadrupole never reached the set temperature of 150 (stayed around 80). I was told main board or side board by agilent. Any ideas or suggestions in case its something I can try to reset. I have already redone the pump down after opening the system back up and checking connections and changed out the heater source assembly.

I vented the system last week and cleaned the source, during pump down the temperature (actual) reading for the source heater was bouncing around between 170-500 degrees (set at 230) and the quadrupole never reached the set temperature of 150 (stayed around 80). I was told main board or side board by agilent. Any ideas or suggestions in case its something I can try to reset. I have already redone the pump down after opening the system back up and checking connections and changed out the heater source assembly.

If the heaters are new replacements, then remove the covers on the side board and find the pass through connectors and see if there is voltage being applied to the heater elements when it should be heating.

Was the temperature fluctuation in the source rapid or over several hours? If rapid I would suspect a problem with the thermocouple or the circuitry that reads the temperatures from it.

It sounds very much as if you did not get a good connection when you reconnected the heater sensor. Opening up and doing it again will surely work out a lot cheaper than a new circuit board.

Peter

Hi

As suggested check the thermocouple and heaters first, they do break on 5973s and can be replaced. Also check the ribbon cable that runs from the side board to the mainboard.

If the temperature is fluctuating rapidly, I would bet that it is the thermocouple is shot. I've seen it happen several times.