My cheap E-Fy 4channel radio (4BII - ETB62, the one that comes with RTF "products") started behaving badly.
It had the glitching-servo problem for a while, but now the resolution is significantly reduced, to the point that the radio is useless now. For instance, rudder stopped working in one direction. When I connect it to the PC and check the gamepad calibration screen, neutral rudder sits at "54", full-right drops that to "52" (should be 0?) and full-left makes it 74. (Should be 100?)
Similar problems with the elevator and ailerons, they are a bit better though. Throttle seems unaffected, at least the resolution drop -if exists- is not very noticable on the calibration screen.
I tried opening it up and cleaning the board with an old toothbrush and isoprophyl alcohol, didn't work. While I'm at it, I tried shorting the rudder pot, while connected to the PC, the range didn't improve (52-54-74, still) so I'm thinking the pots are fine and the problem is with the PIC, firmware (calibration gone?), or some failed passive element near the PIC. I checked the dip-switches and pot-to-board cable connections with the multimeter and they all checked out.
This all started with the radio getting in a weird state, with blinking led and no response. I managed to fix it by toggling the dip-switches while it was on, and then this problem.
So, any ideas?
My brand new 9x is still in the mail, I've been waiting for 2 weeks now (without logging any "flight hours", even in the sim ) and it will probably take another week to get here. But, if I could salvage this radio, maybe I could pass it on to someone to start them in the hobby. It was a gift to me, afterall.
Here's a picture of the board, click to enlarge. Don't mind the scuff marks, turned out they were flux, cleaned right up with the isopropanol.