Hello Alexander,
Sorry to hear that your QDX failed.? Based on what you have described, I believe that Q7 failed when or more of the BS170s failed.? I would be prepared to replace all 5 of the transistors.? This was most likely caused by a higher than tolerable VSWR.
To start, remove Q7 and see if the BS170s drain pads still show as shorted to ground.? If so, then remove all 4 of the BS170s.? With them removed, and Q7 is repaired or replaced with a temporary diode for reverse voltage protection, power up the QDx, and see if the current has dropped to below 150ma and the LED comes on solid.?
The next step would be removing IC5 if the LED did not come on.? Verify that IC2 output is now 5volts after removing IC5.? If so, the LED should come on, and the receiver should work.
If the LED does not come on, then most likely, there are many more failures, and I am not sure it is worth trying to repair.
73
Evan
AC9TU
