We have an Arrow 500 ERO. When the CRT in the touchscreen went out we used a regular monitor to display the screens and used the touchscreen to activate the inputs. Now the system boots up and the self diagnostics show the KT/touchscreen missing. I've checked all the cables and all of the DC voltage levels leaving the A2100. Does ths mean the KT card is dead or is it the touchscreen? Is there anyway to verify which part is defective? What are the upgrade options?