I see this for sale for 125 bucks at http://www.amazon.com/Samsung-HMX-W300-Waterproof-Digital-Camcorder/dp/B007261A6I and given what service counters charge for out of warranty things, that's your cheapest fix from what I can tell.
There are 5 models listed at http://www.samsungparts.com/ModelList.aspx?Catalog=Parts_and_Accessories&model=HMX-W300 and I spotted a SERVICE MANUAL in the first model. As a repair tech, you'll want that.
I recently downloaded the latest manual for my HMX-W300 and spotted the Firmware section. I upgraded using the November 2011 firmware using the SD card method. and only spotted afterwards that it was a much earlier version of the one previously installed. It bricked it and it won't switch on. Tried everthing, including battery removal.
Any ideas ? It is a 30 fps US version. Samsung said I need a new main card!! Unfortunatly, it is well out of warranty. I can get the previous firmware version from Samsung but can;t load it. Is there a boot loader mode? Tried all the normal button combos
Samsung have since listed the correct firmware on their sites (US and UK), But the file is not linked (typical) so don't bother trying it!!