Ok, gotta' ask...
You are aware that this may not be the proper location in the forum for this thread, you may want to Segway over to another board - IN This Forum - so we don't bother those that may take offense to this procedure...
Open that baby up and tell us what you see...
What you tell us, can help us, tell you from us, what can be done...
There are at least 3 types of Pro-520's out there...
AXL - kit with an antenna
XL - basic Radio
XL model though - came in several "flavors".
One was Discrete - I can help you with that -anyone can - for they can be "jumped" with an RC mod for swing and power adjustments for matching to a Leen-yar..."
Another was more compact and used a lot of surface mounts - but you still had some breathing room to remove a coil that went to the Driver so you can still install an RC mod like above.
The ones I'm seeing lately are SMD (Surface Mount Disasters) meaning they have all the small parts and coils fixed onto a single board and no way to modify it easily using everyday household tools, cleaners and small power tools...
So, do like they do at those car dealerships - open the hood, snap a photo or two - and let us know what you find...
:+> Andy <+: