I broke my uCurrent Gold - I think?

[JohnAdriaan]

I've only had it a couple of weeks... It worked fine, but now it has a negative 5.5-7.0mV bias.

Rev 5 PCB, Serial #004118, Cr2025 @ 2.8V (when on, on mA range)

With my multimeter on mV, connected to the Voltage Output terminals, and nothing connected to the Current input:

• When OFF, it reads 00.00mV
• When ON, it reads:
  
  • nA=+04.45mV
  • uA=-05.50mV
  • mA=-05.50mV
• When SHORT, it reads -05.60mV.

If I measure a 5.03V source through a resistor, I get

• 5.03V through 10K (9,998ohm) resistor on uA scale:
  
  • Floating=-07.02mV
  • Connected=+507.0mV
• 5.03V through 1K (993ohm) resistor on mA scale:
  
  • Floating=-06.66 mV
  • Connected=-01.61 mV

I'm perfectly willing to accept that I've blown something: but what? Where? The fact that it still measures reasonably accurately, but with a -6mV bias, is both humorous (-06.66V) and factorable when measuring, but it is a little irritating!
With thanks for any suggestions

[evava]

Try looking on output with scope, if it is not oscillating.