Hi, :)

- First test your batteries on load(connected to a load) .

- Check the batteries connection (flat-flex inside the batterie older (often corroded)

- remove the rubbers pads and unscrew the four vises (on the bottom), and check the flat-flex connetion on the main bord (alsow oftem corroded on this place).

If the flat-flex is not to much corroded, you can try to clean it, and the contacts (never use solvent on the ff).

- Take attention that the four vises apply a "pressure" on the flat flex (a kind of spoons on rear of the ff, maintain "flexible pressure"), check that all :)

Ok , let me feedback with your instigations

(i could send you link of tuto to fix this kind of flat-flex problems).

Regards , PVR