I am using the 8900 ICP-MS. I am getting error 1134, gate valve not opening. The argon pressure is within range. I even vented the system and manually tried to open the gate valve from the maintenance menu and that did not work either. The error says it could be the connectors, solenoid or the gate valve itself. The connectors seem to be ok. Has anyone changed the gate valve, is it relatively easy to do?