Merit G21-100-001 Touch controller failed error on startup

[electronicsguy]

I just purchased this game and when I boot it up I get the error message that the touch controller has failed. Before I buy a new controller does anyone know a way to isolate if it's the touchscreen, controller, or motherboard? I tried unplugging the whole controller, then the touchscreen, the error is there no matter what. I'm wondering if I get a serial mouse if it will recognize that enough to boot up and see if the rest of the unit works ok. Is there a way to bypass that error during startup?
Thanks

[electronicsguy]

I did end up fixing this in case anyone else runs across this issue. The brown wire from the touchscreen had came off and fell down to where it was touching the bell of the crt and when the high voltage came up it spiked the microtouch controller. I checked and found 12v getting to the controller but the led never lit. Upon disassembling the controller there was a shorted SMD electrolytic capacitor. It measured 30 ohms across it out of circuit. After I replaced it I had 12v going into the nearby 7805 regulator but nothing on the output side. I removed it and checked it and found 100ohms from ground to output, replaced that and an smd resistor in line with it and it is working fine now.

[Chris-socal]

Good detective work. One wire!