I finally got around to repairing my Trio R1000 receiver which was intermittently locking up with a frequency reading of 39Mhz. Sometimes a good tap to the side of the receiver cured this but the fault always reappeared. Research on the internet showed this was a common problem, normally caused by dry joints on the power board.
I removed the power board and remade some of the joints below the multi way connector on the board. This did not do the trick unfortunately. I then turned my attention to the two transisistors you can see on the heatsink in the picture. Re flowing the solder on the underside of the board here has cured the fault, for now at least and the R1000 is sounding good again. Now I notice that the S meter bulb has blown so I either need to find another bulb or maybe try an LED as a replacement.