Praktica light meter problem

Hi, i just bought a Praktica MTL5, it needed a battery for the light meter, so after some searching i found that i needed a 1.35v battery, so i ordered one which came today, i put it in and tried the light meter button, but the needle just jumps straight up to the + symbol, doesn't matter what settings i put the camera in, the needle just goes right up, anyone got any advice?

If you set the film speed to 400 ASA and the shutter speed to 1/4 of a second, does the meter needle move? If so, the gears that drive the light meter potentiometer have cracked. It is possible to replace the gear and axle assembly from a Praktica junker. Just a heads up, the gear plastic is coal based and isopropyl alcohol melts them.