Yea this modem get a bit too hot, it's was restarting most of the time, so I install a fan and few heatsink too cool it . now it run like a boss .... no more restart
in the pic you will see two small hole you route wire to the back of the pcb , and there , will you have to solder wire on the board like on the pic... There enough solder you can use on the board already there
by the way my motorola modem is SB6121 and my fan is mounted on the side and wire to pcb it was e-z to wire thay way..... Dust is e-z to blow off from in side, out