MT2400 power graphing multimeter

[R_G_B_]

Hi thought I post here as well maybe someone can help this odd problem:

MT2400 power graphing multi meter with a problem:

It will not measure AC voltage or show AC signals on channel 1 when you select the AC measurement function.

However it does show AC signals when in other modes e.g if i go to the menu and select AC pulse generators then channel 1 will happily display AC signals.

Also Channel 1  has no problems displaying D.C signals and D.C measurements.

Note only channel 1 is designed to measure AC signals. The rest of the meter seems to function OK.

The input coupling to this graphing multi meter is D.C on all channels. To get AC coupling requires an AC filter as shown in the link below:

I have tried to supply a pure A.C signal to the input channel 1 it will not read or show the signal when in AC measurement mode.

http://resources.aeswave.com/old/TechNotes/index1.htm


Could this be a firmware issue or corrupt data in the memory eeprom card?

R_G_B_

Thanks