Reply to technics weight/set up problem

Hi on my 1210's the tone arm weight (on both) are pushed the forward until it stops and set to 3.5, but it's still not enough weight for my cartridges, both to jump or come off the vinyl when let say I am cuing a track. Stuck a coin on them (dont want to do this really) and they stay down. i have also looked at various Youtube clips on how to balance/set up but both my turntable fail to operate like this.

Any recommendations or do they need repairing?

Ps I have technics head shells and Stanton 500v3 needles.