i would check the fuses in the main panel as i guess 1 of them may have fused. u will need to unscrew the lid from the main panel and check the fuses inside and replace it.
i put up a link its the manual check page 8 its got the pcb diagram showing the fuses.
http://www.spyalarms.co.uk/wp-content/uploads/2010/10/Veritas_R8_manuals-1-.pdf
fix, January 2013