+1 Adrian. My 20m QCX had the exact same problem, and replacing those caps fixed it. Just did this on Saturday.
Even with the bad caps in there and only getting around 1.5 watts out, I still managed a SOTA activation where I made almost 20 contacts (one of which was Japan). The rig should really be ripping it up now, with 2.5 watts @ 12V =)
P.S. here is what I did for a case on my QCX:
https://drive.google.com/open?id=1NVteslv5SlAQxhVJqh8izM3Hx01wmTeO
Got that box from Amazon - its got a rubber gasket so should be very water resistant. It tends to rain a lot here in W7W, so this should be a good foul WX SOTA rig.
-Josh WU7H