I've had the dreaded value encoder problem for a year. I could fix it temporarily by spraying it with electronic cleaner and wiggling it around, but the problem always came back.
Finally, I decided to man up and just replace the encoder.
Thanks a lot LiPI for posting your experiences in this thread, and thanks Timo for posting the
"Inside the Radias" thread. It was really helpful to know what to expect when going in.
I didn't have much problem disassembling the Radias to get to the bottom board, it was easier than expected to take apart the boards and reassemble them as long as you keep track of which screws go where, there's a lot of different screws. As LiPi noted, the hard part was getting the old encoder loose. (More on this below)
Anyway, here is a quick step by step if anyone else needs to replace their encoder. If you decide to go for it, wear an anti-static wristband and make sure you don't overheat any nearby components.
1. Turn the Radias upside down. Use a couple of books under the rack ears so you don't damage the pots.
2. Remove all the screws (make sure to note down which screws go where as there is a lot of different ones).
3. Take off the bottom metal plate.
4. Disconnect and unscrew the long narrow circuit board with all the outputs.
5. Unscrew the smaller DSP circuit board and remove it carefully. The boards are connected tightly with a 50 pin connector (on the right here) and you definitely don't want to bend the pins on that one.
6. Unscrew the metal spacers, then remove all the screws that hold the big circuit board in place.
7. Carefully lift out the big circuit board. It's long and fragile so make sure you are careful when handling it or you might break it.
The encoder on the top right is what you're going to replace.
8. Here you can see the underside of the board. This is after I've removed the old encoder and soldered in the new one. These 5 solder points are what holds the encoder in place.
9. Here comes the hard part, getting the encoder loose. You have to desolder the three small pins and two big "grip" pins. If you don't get all the solder out, it's hard to pull the old encoder off. I had to cut a couple of the legs of the old encoder to be able to wiggle it free. (There is a product called ChipQuik which supposedly can help with desoldering multiple points, but it's not something I had available).
10. Clean up the solder points.
11. Mount and solder the new encoder.
12. Put everything back together. Be extra careful when putting the DSP circuit board back on, so you don't bend the pins on the 50-pin connector.
Good luck!