[Sergio]

Perhaps PingEye3 has seen that model, I have not.

You can always try each trim-pot.

Place your voltmeter on the charger output and leave it there.

Use a small screw driver to turn VR2 slowly clockwise half-turn at the time up to two turns.

If the voltage goes UP, then turn it counter-clock-wise.

If the voltage does not change, put it back in the original position and try the the same procedure on VR3 then VR1.