I'm working this radio which apparently had a hard life or was a depot parts swap set.
i have both the 900 and 900 dx manuals, but I have found the regulator and the spectrum gen boards to be different than what the manual depicts.
Even the filter assembly is radically different , having the older motor driven filter select  instead of diode switching.

The spectrum gen says 1A4A1, rev-J
Anyone have a schematic for this rev?

The way this is going I may need info on other rev boards too, if you have them.

thanks,
Jim, AC2EU