My laptop has a bad power jack where the power cord plugs in. It does not get power when the cord moves and sometimes when the computer is not moving the power will be lost to his computer. I am trying to install Gentoo from source and cant keep keep my computer on long enough to do it. What can I do? The laptop is a Toshiba. I know I am supposed to solder, but what and how? I am guessing the something inside the little box (power jack) on the motherboard needs to be soldered. How do i get that opened?

Rather than the jack I'd suspect a broken core in the power cord. You can try putting a volt meter across the power plug and wiggling it around. See if you get interruptions.

Alternatively can you borrow another power supply?

If it is the jack socket that really is the problem it may be very difficult to get at. You should seriously consider a professional repair.

Agreed. Cables wiggle, and are thus more exposed to stresses than sockets.

It's very common for wires to break within a cable (that's one reason why multi-core wires are often used for power supplies, as well as the better current distribution).

To get at the socket depends on the layout of the motherboard/PSU. This generally involves opening up the case, taking the machine apart in order to get the motherboard and/or PSU apart and then looking at the jack socket. You'll soon see if anything is broken.

CAUTION: Many PSU cases bear big warning labels on them saying things like “do not open” and “danger of electricution even when turned off” (depending on the type of supply). These are less common in laptops, which tend to put the high-voltage stuff inside the cable, but you may still need to open such a case to get at the socket. If so, read the label, pay attention to it, and make sure you know what you're doing before deciding to open it. Neither I nor LQ takes any responsibility if you break something or get yourself electricuted.