Mastech MS8212A Pen type multimeter doesn't switches ON normally

[abhishekkumar1902]

Hello Friends,

I have a Mastech MS8212A pen-type multimeter which I bought two years back, didn't use it at all but kept it in there as it is with the batteries removed.

Yesterday when I put on the batteries and tried switching it ON, it didn't turn ON at all. I tried with another set of batteries, also with a bench power supply as well, but it didn't switch ON when the rotary knob was turned to any of the four working positions. However when I press those MAX, RANGE, etc buttons, they gave a beep sound that means the circuitry was at least turned ON but nothing o the display.

After a few hit and trials, I observed that the multimeter switches ON successfully when I QUICKLY (like within 500 milliseconds instantly) turn the rotary knob to either the LOGIC or VOLTS position, and then it continues to work in all other four positions until I turn it back to OFF position. However, it does not switch ON if I normally turn the rotary to know to any of those four working positions.

Issue video: https://youtu.be/90gSqvFYX7w

What could be faulty?

Any help is appreciated 

[crastor]

I am a hobbyist electrician. I have a Fluke 116/323 kit HVAC Multimeter. I think it's one of the most reliable brands on the market.

• Measure 400 A ac current
• 600 v ac, and dc voltage.