Another thing to check is the SMA connector jumper. Sometimes, it will become loose and will show very low output. The SMA will be tight, but the little jumper will not make contact. Not the connection to the board, but inside the SMA. You have to dissect it a little to see what I'm talking about. This is usually from radios that have been abused, i.e., dropped a lot, or from a radio being opened a lot. Flexing that jumper over and over will break the connection. I saw this a lot on the bench.