Keithley 2400 - Voltage Offset

I am using a Keithley 2400 to perform I-V curve measurements and I have come across an apparent voltage offset that is causing the voltage source setting of 0V (on the screen) is actually sourcing around 0.7V. I am working on generating a curve to account for this offset but I was wondering if there was a way to remedy this without needing to send the unit in/pay a bunch of money. I am allowing it to sit on for a long period of time as it does drift. Using an external multimeter to measure the actual voltage being applied to a resistor.

An offset of 700mV is quite large for any of the ranges.
I'd say it is unlikely to be a calibration issue.  It most likely requires some service.

Humor us and double check the setup.  From power on default behavior, if you just turn the output on (blue light) it would be configured to source 0V with current limit of 105uA.
Do any digits on front panel flash rapidly?
And if you connected a voltmeter to the HI and LO, you see 0.7 volts instead of 0V (don't use the resistor)?
Is it a constant amount of offset....if you asked the 2400 to source 1V, would you get 1.7V?

Booting up as you mentioned, no flashing digits on the panel. Connecting directly to voltmeter I am reading 0.734V. Offset is certainly constant. I have left the machine on for over 24hours to see the final value that it drifts to and it appears to be the value I mentioned. For what its worth, if I measure the voltage on the Keithley simultaneously, it reads 7mV with Vsrc at 0V and external voltmeter at ~0.73V.

If the 2400 is reporting 7mV, then it thinks it is doing good job (within the source spec) of enforcing the 0V set point.
But your external voltmeter tells you there is a very big error.

I'd be skeptical of overall performance and would check the various source ranges and measure ranges you intend to use.
Connected a trusted amount of R between HI and LO to validate if the current measure is correct (for the voltmeter reported voltage).

The amount of voltage offset you have is well beyond amounts that are corrected by calibration.  I suspect some sort of repair issue in your unit.

 

I've checked and trust the current measured is quite accurate. I can easily use software processing to adjust the offset by changing my applied voltage parameters, it is slightly annoying but usable. Any chance I could be pointed towards what might need repair within the unit?