Craig,
Not sure if this helps, but occasionally when I switch on my serial ST2 + G5400 rotator, I get the same blank screen. I am able to clear it by turning off the G-5400B controller, unplugging the ST2 at the USB plug (its on a prolific serial-usb adapter), and then turning the G5400B controller back on (I power the ST2 directly from the G5400B). The screen comes back, and then I plug the USB adapter back in and I can use the system normally. I suspect you've already tried stuff like this already, but worth a shot. Good luck.
--Roy K3RLD
Hello fellow satops. After thinking I had fixed my Fox Delta ST2 calibration/runaway readout problem (worked for "a while"), the problem started up again. With much help from Dinesh VU2FD and Frank K7SFN at FD, the epromm was reprogrammed, thinking maybe some rf got into the ST2. Unfortunately, now there is no readout on the ST2 display, although it is illuminated, and I cannot manually bring up the calibration screen (or any screen). The front buttons on the ST2 are inoperative. The DIN plug connections between the ST2 and the G5400 are solid. The G5400 controller and rotors all work as they should using the Yaesu controller box. Not sure how to go about doing any further troubleshooting except maybe to check voltages on the wires coming from the G5400 through the DIN plug to the screw strip on the ST2 board. I've got my money's worth out of this great little box and don't mind getting a new one (this time, the USB version), but need to first eliminate the G5400 as the issue.
If anyone happens to have info on what voltages I should be reading on the cable/ wires from the G5400, that would be very helpful. I assume some of the voltages will be variable based on rotor positions. I checked the G5400 manual but it does not appear to provide that information without analysis of the schematic. (beyond my skill set)
Any suggestions would be greatly appreciated.
73, Craig N6RSX