mitsi heavy centralised controller issues

greetings
customer has a vrf system with no local remote controllers-1 centralised scsl3na-ae
approx 18mth old- software version 3.10e
checked the time schedules and all the kit has to start up at 1am as the building fabric is poor- high ceiling void- uninsulated ceiling tiles
monday,tues morning- staff say controller locks up- touching the screen doesnt light up- they have to remove the front cover and reset it on the rocker switch- im going to site again tomorrow at 7am to hopefully see this
ive checked connections on the back of controller,comms ok

previously when this happened they installed a ups to ensure power to the controller as they think it could be mains incoming issues- media city is 300yrds away so probably the bbc zapping al the leccy
when it resets the time/date is correct- it times out for 240 secs whilst it reboots
feel free to suggest
oh and no fault codes stored- all works ok once rebooted
ps i didnt fit it:p

found operation manual states it could be electrostatic discharge- would wrapping the power supply 3 times around a ferrite core fix this?

Typical- on site all working!

Whats the system? All indoor and outdoor units same series? SL1 or SL2?
The controller may overheat due to the lack of air circulation.

hi ruskbuka - controller is in a plastic enclosure- it is warm inside- but not toasty
all indoors are same series- think its a kx4 outdoor- comms line isnt grounded at the controller has run all day ok, suspect the comms line and the mains flex in the wall is causing problem- if it comes in again then ill run the comms externally to see if that cures it