vantage digital multimeter

I have a vantage digital multimeter which I believe was bought in the late 80s. I had never used it as I was always busy in life for living. So it has been put aside for many years. Learning Electronic as a hobby was only a luxurious passtime to most young urban yappies. So happened I wanted to test the PCB components and the thermal sensor of my induction cooker. Therefore I grabed it out from dusty toolbox. As can be seen the batteries and their contacts were tarnished. I checked my home battery pack and the batteries there were also tarnished. After putting the good batteries in, the vantage Kaise SK-6511 is back to live. After all, it is a Japan make.

Post notes:

I have my IC dissembled. I tested it and the result confirmed my guess. The triode 8050 (SS 8050 331) is gone. I am not going to fix it as my soldering skills can never match those female factory workers in the 70s. Therefore I need good tools or I pass it to an electric technician.