Hello, here are the error codes that the self-test throws. I think that’s nearly all except for the AD-Converter ones. Does anyone have an idea what could be possibly wrong or what I just can probe? The SMU itself luckily works just fine but the accuracy is not there as it should be even though it is freshly calibrated with my Keithley 2001. Below are some questions about the error codes too.
200.1 200.2 200.3 200.4 200.5 200.6 200.7 200.8 => AVM DAC (What exactly is an AVM DAC?)
201.2 201.4 201.5 201.11 201.12 => IDAC
202.2 202.4 202.5 202.11 202.12 => VDAC For example, error code 202.5 says -4.916392, but expected is -5.51000 +/- 0.12500. It is always slightly off the nominal value. That’s for nearly all tests.
300.1 => F/R 2W/4W
301.1 301.3 => 200mV Range
302.2 302.4 => 2V Range
303.2 303.4 => 20V Range
303.4 => 9.863552 Expected 11.056 +/- 0.25000 For more values, please comment 304.2 304.4 => 200V Range 400.1 400.3 => 1µA Range 401.1 401.3 => 10µA Range 402.1 402.3 => 100µA Range 403.1 403.3 => 1mA Range
404.1 404.3 => 10mA Range
405.1 405.3 => 100mA Range
406.1 406.3 => 1A Range
500.1 500.2 => Volt Clamps
501.1 501.2 => I Clamps 502.1
502.2 502.3 502.4 502.5 502.6 => AVM Clamps (What exactly is an AVM Clamp?)
600.1 => AFB Signal (What exactly is an AFB Signal?)
My question is what could be wrong in this unit throwing so many error codes and still outputting voltage and current?

Any suggestions for the fault help are briefly appreciated.
Did some thermal imaging and some probing of the common test points but nothing found so far.
Best Regards
Stefan