It is always annoying when something breaks.
It could be that there is a defect in the DC-input of your DVM-190.
You can check this by inserting the adapter pin in the DC-input of the monitor and gently move it up and down.
If you see a charge indication while moving up and down, the DC-input might be broken.
You can then report your unit for repair via this link.
Through this repair form we will have all the information we need to help you.
Please make sure that you clearly describe the problem you are experiencing, so that our technicians know what to look for when repairing the unit.
Should you have any additional questions, you can always contact us via this website.
Please state the complaint clearly so that we can help you.