Unstable 49G

[Tugdual]

I had something very similar on my old 48g. While I don't think the two machines share a lot in common, may be it can help you to know that the issue was a defective electrical contact on batteries. I used sand paper on metal plates that were corroded and the 48g is kicking again. I guess the 49g is using springs like the 50g but you might still want to investigate in that sense?