To make it more useful for you, I have included the disassembly here with photographs of the process and the board in case you have any desire yourself to do additional modifications. If you do any such modification successfully, please drop me a line with what it was and we'll see about posting it here too.
Thanks to Cameron Bean who provided suggestions and some of the tools here when I was over at his place (where said power pin originally snapped, in fact).
I'm receiving quite a bit of mail about this, all of which seems to indicate that this particular problem with the power connector pin is a very common one. I am also informed by reader Howard R that this fix will work nearly identically for the RM300. Naturally, all standard disclaimers apply, you do this at your own risk, and this is definitely not a repair procedure endorsed by Thales-Magellan.
Remove the four screws from the "corners." You don't need to take the screws
out from the attachment plate. Pop out the SD card at the bottom (under the
rubber cover on the opposite edge from the antenna, not shown here). Note
that this alone might void your warranty; there is a sticker on mine that
popping the card out will tear (and did). You might also want to pop the
antenna off at this point.
Entire original image (100.3KB)
Separate the halves. Note that I just pulled the antenna off with the entire
bottom half in one "piece," but you don't have to do that. The speaker cable
can be left connected at your option.
Entire original image (115.1KB)
Lay the "top" (screen) half down flat. In this view, the USB and power
connectors are on the left. To get at the power pads, we need to get the
board freed. There are six screws, starting at the plastic standoff at
top left and going clockwise (above the "11|QC," then just under the
upside down 211906A, then next to the speaker connector,
then between the antenna connector and the plastic
standoff at lower right, and finally below the USB connector on the
Entire original image (99.1KB)
I point out the one at 11|QC specifically because people can easily miss
this when disassembling it. I know it took me a little while to spot it.
Entire original image (67.4KB)
With the screws freed, pry the board up. Careful at this point as there is
a ribbon connector to the LCD display which is thin and fragile, and the
button panel likes to flop around. I rigged it so that the board would just
drop onto the other half with the speaker, which was still connected.
Entire original image (102.7KB)
The power connectors are those three small solder nubs at the bottom left. To
get to them more easily and avoid damaging the power switch, you might want to
pry up the top contact sheet of the switch and hold it carefully to one side
with a clamp. If you choose to do this, you will probably need to reattach it
with some sort of adhesive (krazy glue was convenient). Do not try to take
the metal contacts on the sheet off.
Entire original image (67.2KB)
Strip back the car power cord (or what have you) and solder the positive lead
to the centre connector terminal, then reattach the contact sheet if you pulled
it up in the previous step.
Entire original image (71.8KB)
To make sure that you didn't mess the switch up, you might want to touch the
negative lead to its terminal (I just did this inside the power jack itself,
and make sure the unit can still power up when the switch is depressed. The
bright blue LED here shines brightly even in this flash photo.
Entire original image (51.3KB)
To avoid having to drill a new hole, I tore off the top of the power jack
and threaded both leads through it, soldering the negative lead to the
side contact. This means both leads can run out the same original hole.
If, however, you have removed or wrecked the jack, or made it otherwise unsuitable, you can still use the other solder terminals next to the positive terminal, or as reader Herb B reports, just create your own: "Since I had removed the remnants of the power pin, I had 3 holes on the circuit board. The outer 2 are ground. So, I made a horseshoe piece of wire and soldered each end to the outer holes and then soldered the ground wire from the power cord to the horseshoe wire. There is enough room for everything to lay flat and not make contact with each other. The unit works again, but I will add some type of strain relief clamp to support the power cord to avoid pulling on the wire soldered to the circuit board."
Entire original image (66.7KB)
Replace the circuit board screws, reconnect the speaker cable (if disconnected)
and replace the bottom half, antenna and outside screws. Plug it into your
car's power source or an external transformer and hope you didn't kill it.
Entire original image (44.1KB)