Is my DMM kaput?

[Turbo DV8]

I was trying to measure the current at the tail cap of a small 5mm LED light. On the 10A setting, it drew 110 mA, but when I switched the leads to the 200 mA side and switched the setting, it read 67 mA and the LED barely lit up. Is something amiss?

 

[Light Sabre]

Nothing is wrong with your DMM. Different values of resistors are used for each setting, so getting a lower current reading on the lower current scale is possible especally on an older DMM. The newer DMM's are a lot closer, or exact in some cases. Depends on manufacturer and $$$ of the meter. The lower the cost, the more likely this type of thing is to happen. The measure the voltage drop across an internal resistor to calculate current. The 10A scale probably uses a resistor in the milliohm range, the 200 ma scale probably uses a resistor in the ohms range. At such a low current the difference in resistance of the 2 scales is significant. I would trust the 10A scale 110ma reading over the 200ma scale 67ma reading. You need to know what the limitations of the measuring/test equipment you are using. Use another DMM on the ohms scale and measure the ohms across the 10A and 200ma scales and you will see what I mean.

 

[Turbo DV8]

I would trust the 10A scale 110ma reading over the 200ma scale 67ma reading.

Thanks for that. I assumed to believe the 110 mA reading, since the LED lit up normally, and on the 67 mA reading (200 mA setting) the LED did not function normally. Does this have to do with percentage of voltage drop across the DMM internal resistor leaves not enough of the NiMH 1.3v remaining to forward bump the LED?

 

[Light Sabre]

Yes. The internal resistor of the DMM on the 200ma setting would decrease both your voltage and current going to your LED.