From the manual (http://pdf.crse.com/manuals/3251114211.pdf 4mb) here, it says that 'FAILURE" means that 'the connection of speakers / amplifiers is incorrect.'
Did you change the wiring when doing the neons?
How about the grounding for the neons, is it to a clean spot secure to the chassis?
Is the neon power wires anywhere near the amp wiring? Try moving it away...