Hey, I see what you mean about complicated, haven't given any advice in a long time
😛I wasn't sure if your power connector was actually broken or if it was not working well. So I described every possible scenario I could think of.
The power connector is attached to the motherboard. If it broke, it can be replaced without having to buy a new motherboard. Since it is on the edge of the mb, there aren't a lot of things around and it is a big piece, it is a relatively easy job for someone with soldering skills.
Here is a link to the original connector of the g73x:
http://www.ebay.com/itm/DC-POWER-JACK-ASUS-G73-G73S-G73SW-G73W-CHARGE-PORT-SOCKET-CONNECTOR-REPLACEM...If you look closely you will notice a tiny yellow pin. That is in charge of supplying all the positive charge to the motherboard. If you look around the forum you will find dozens of people that had to replace it.
Given that this connector failing is a common issue, replacing it with the same connector may result in the same problem after some use. That is why I recommend placing a generic 5.5 / 2.5 mm female connector instead. This is the one I installed in my notebook (it is a g53, but it has the same power connector issue as the g73):
http://www.ebay.com/itm/10PC-5-5-mm-x-2-5-mm-DC-Power-Jack-Socket-Female-Panel-Mount-Connector-/2611...It is a bit more complicated to place a connector that is not meant to be there, like the original one. I had to solder wires from the connector to the motherboard. Also it didn't fit threw the whole, I had to make it thicker with a knife. This is what it looks like on the outside:
So, if you can trust your repair shop to do a nice job you may want to go with a generic replacement instead of an original one. If you do so you wouldn't have to worry about stressing the cable anymore.
As for the 90 degree cable, I never understood how that could relief the connector of stress, but I'm no physicist. Perhaps it does help somehow, but I think the safest bet is to place a tougher connector rather than to prevent any sort of stress that may happen from external forces. Since you already have to replace it and you are not going to the warranty, it seems like a nice idea.