Hi Number15, I came across the same problem with my DX99V. It was used, and at a price of $20.00, I could not say no! Everything worked Great, Until I hookedit up to my Wilson Beams. Everything still worked, but I had an intermentent short on USB recieve. I broke out the magnifer glass, and asked the former owner had it may have been dropped by accident? He forgot yo tell me. Convenient for him, and a lot of sore eyes for me!
I was able to find a "Hairline Break" in the board! I scaped it clean with my trusty Exacto Knife, and a tiny drop of solder, I was on the road again! Finding the crack was the hardest part! He Peaked it beyond all specs, also. After putting back t Factory specs, I cut the power bak, (saves on the RF Power transitors). Works Great now, and has since I bought it over 3 years ago! Hope this may help you.
73, and TC..