It needs two PC640A alkaline cells or PX640 mercury cells to operate. Both of them have extinct for years. Without the batteries, the metering and the shutter won’t work. There are many rangefinder lovers invented various methods to DIY the Yashica 35 GX battery replacement.
A replacement cell for the Yashica 35 Electro GX can be made in a dirt cheap way.
Cut two short sections of water pipe. The inner diameter is about 1.2cm. The outer diameter is about 1.6cm. It does not need to exact.
Also, you need some tin foils.
I used the very common LR44 cells.
They can fit nicely in the tube.
Stuff a tin foil in another tube. It is the conductor to complete the circuit.
They can fit easily into the battery compartment of the camera.
The battery level looks okay.
The metering is fine. See the orange arrow light.
The PC640A or PX640 cells are 1.4V cells. The replacement by LR44 is 1.5V. It makes the overall operating voltage increased from 2.8V to 3V. It may make the metering a bit inaccurate (the higher voltage may give shorter exposure and darker picture) but the deviation is so small that you may not notice it.
See some of my black-and-white at my Pinterest page.
Thanks for reading. Let me know if you like it.