I have a 492 unit that came with my ETX-125 ( i also got a 497 with it ), and on starting up, it automatically does a calibrate on both axes, so "should" reset the encoder leds accordingly.
Do you see/hear the calibrate process???
That said, there is no way to set any ratios in the 492, and IIRC, the ratios hardcoded in them ( at least mine ) seem to match the later models of ETX-70,90,105,125.
I dont know if there were different variants of 492 for different models, but my notes show the ETX-60 definitely has different ratios and hence will not work with my 492.
I also have notes that there were 2 models of ETX-70, but with different gearing in them, and the older ETX-70 matches the ETX-60.
By any chance, does yr 497 Hbx have our patches loaded.????
If so, there is a diagnostic tab at the back that can read out all the details, and i would need to know what motor card type was fitted, as that determines what ratios etc can be selected.
Andrew Johansen Melbourne Australia