Chromatography Forum

Hi All,

Currently having trouble maintaining pressure on our 7890A CoC inlet.

What happened was we wanted to swap the back inlet (originally the CoC) with the front (originally a SSL) for maintenance purposes. This was carried out by the contractor.

What happened was a drop in flow to the CoC inlet after a run.

My trouble shooting has found that it only happens post run.
I can change settings via the keypad to simulate the temperature and pressures but no pressure is lost.
I have run isothermals, post-runs that are meant to keep pressure while cooling, higher and lower pressures.

I am thinking it is a software/electronic conflict at some point, and FYI the conflicts of inlet swap were resolved in the methods we use on the software, but is there something we missed?

Will running a sequence solely from the GC keypad identify a software issue if a run was successful?

Also the only way to get pressures back up is to restart the GC, I cant just reload the method on the software to do it which is really annoying.

Resolved.

it was a conflict caused at the switch over.

GC firmware was v9 where latest is v14. GC flashed with the new firmware and is working correctly now.

The technician hasn't come across this error before. Hope the solution helps others.

This is good to know, thanks.