Hello, we have an Agilent 6420 and after one weekend we came to the lab to see that the rough pump was not running and appeared to have no power as well as the turbo pump controller with no illuminated LEDs on the front. The rough pump (MS40+) receives power directly from the LC/MS power output. We plugged in the rough pump directly to the wall and it is powering on and running fine. We checked the voltage on the back outlet from the LC/MS that provides power to the pump and there is no power. We checked and replaced all fuses on the PCA. We then replaced the PCA with a new one and we are still not getting any power to the MS40+ from the LC/MS. The LC/MS powers up and we can interface with it through a PC just fine. All LEDs on the PCA are green. We are stumped and have stumped at least one agilent engineer so far. Anything else we can try and test?