Hi Herb,

if you haven´t found those already, Agilent has two "troubleshooting"
documents dealing with EPC problems, entitled:

1. Troubleshooting the 6890/6850 GC Split/Splitless Inlet. Actual Pressure
is Higher than the Setpoint (www.chem.agilent.com/cpdocs/a16021.pdf)

and

2. Troubleshooting 6890/6850 Split/Spitless Inlet Leaks. Cannot achieve
Setpoint Pressure (www.chem.agilent.com/cpdocs/a16020.pdf)



Good luck,

Jens 


Am 14.11.2007 15:42 Uhr schrieb "Herbert Tobias" unter <[log in to unmask]>:

> Hello All,
> 
> We are having a problem with the Electronic Pressure Controller (EPC)
> module on an HP6890 GC.  The problem is that it always senses 2.0 psi
> headpressure, but will not increase or decrease, no matter what number you
> set the headpressure to be.  For instance, if one sets the headpressure to
> 0, the measured amount remains at 2.0.  So it is electronic, and not a
> leak.
> 
> We contacted Agilent; however, the only choice is a service call, or buy a
> new unit ($3300).  Did anyone out there experience this problem before and
> have the ability to fix it?  Any suggestions would help.
> 
> cheers,
> -Herb
> Cornell University