I am getting an error on our Agilent 1290/6420 LC-MS/MS. I start a run and the first injection is successful, then when it goes to the second injection, it errors and says "failed switching to main pass" and shuts down. From my reading, this is a failure of the injection valve. We have an Agilent G64226A autosampler. I have restarted several times but this does not fix it. Has anyone encountered this before? How can I fix? Thank you!