Only requires a small hammer to do the mod!
If at first you don't succeed, get a bigger hammer!
When I worked F-4 Phantom II radars, the AWG-10, especially the A model, we found that some, easily identified problems actually could be solved with a sharp blow with the side of your fist to the faulting module. I showed an AF crew in Clark AB that trick. They'd never heard of percussive troubleshooting, as we called it. But hey, it really did work
Especially the LRU-11, the display control unit. That thing was severly abused by RIO's. They'd vomit into it, and use some cards as A5-H Receivers (ash trays
). I won't specify just what KIND of ashes we found in them, but there was more than just tobacco, if you know what I mean.
Of course, this was mostly in Yuma, where RIO's, and Pilots as well, got their first real experience flying in the Lead Sled...
Pat☺