P90 mag not feeding - magazine motor runs only some of the time

P90 mag feeds only some of the time
Stopped feeding with gels in motor and can’t get them out
Will sometimes feed for a couple of rounds then stop

Visual inspection doesn’t show any difference to a magazine that feeds perfectly

Tried wiring 1.5 V battery to terminal to see if I get the motor turning at all. Doesn’t move the motor

Assuming it runs off 7.4 V and 1 5 isn’t enough to move it.

Magazine hasn’t been used except for testing today.

Any suggestions on how to trouble shoot appreciated.

Video of Magazine grinding.

Just after I filmed this it stopped driving the motor.

Opened up magazine.

Added lube and and reseated gears to ensure they spun freely.

Still stops feeding occasionally.

Think it might be dry solder joints?