Chromatography Forum

Greeting,
I have and Agilent (HP) GC 6890 and have been experiencing a malfunction in which the system repeatedly runs a my method, even without hitting start. I've disconnected all other controlling system such as the computer or mass spec. The Agilent Tech told me the problem is most likely on the main board and would need to be replace but I was hoping maybe one of you guys had come across this problem before and maybe had a suggestion of repair I could make. I am currently looking at the fuses and 3 volt batteries but any other suggestions would be great.

You may try to disconnect the keyboard , may be a stuck key causing this.

Hello

Few questions:
1.Does GC pass "seltest" after reboot?
2.When you load method or set parameters, have you got it in "ready" state?
3.When does it start your method? After you change something?
You need to describe it more precisely.

Regards

Tom

I switched keyboard on another 6890 and got the same response so I have to guess its more on the board itself, Though I will try to take a look at the key either way. Thanks for the suggestion.

Hello

Try to reload firmware. Sometimes it helps.
Regards

Tom

Examine the APG-remote socket on the back side. If there any cables or stubs?
Shorting to ground (chassis) APG-START line will start the system. Permanently shorten line will cause endless restart.

To answer Tom's question when it starts it goes to run position at the end of start up and "selftest", half way through. I put it into sleep method so I dont have it in ready mode. Basically it does not reach a ready mode at all, it merely stay in run mode. I will be checking the back APG-remote area today antonk to see if the internal connection may be damage. It is completely disconnected from all other systems right now so it has to be the port itself if this is the problem.
Thanks for the advice