Hi Deane,
I do not have a Roland A-800 PRO MIDI controller keyboard.
I have a newer 61-key M-Audio Code 61 MIDI controller keyboard, which has no problem powering up from any of the 3 USB 2.0 ports on the right hand side of the Ketron SD90 module. The Code 61 works fine with the Ketron SD90 module, and there is no frozen touch screen issue.
MIDI out on Code 61 by default was OFF. I had to press the EDIT button, and pressed the lowest B key to turn MIDI out ON before the keyboard could send MIDI messages to the Ketron SD90 through MIDI connection.
Menu - Preferences page of my Ketron SD90 shows:
Rel. 1.1.0 20/07/2018; Firm: V3.0A; Serial: XXXXXXXXX; T=46.22 V=3.02 K.Firm: V1.12
Did you try powering your Roland A-800 PRO from a standard USB charger such as any USB charger for any of your cell phones? This should at least allow you to start playing with your Ketron SD90 without frozen touch screen.
Thanks,
Paul
Edited by zionip (10/23/18 10:02 PM)
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Yamaha Genos, Ketron SD90, Korg Kronos 2 88, Korg PA1000, Casio Privia PX560