SABRE HE?

The red light is on.......it will re start for around 15 minutes then all goes off again......red light comes back on.
2 engineers have no idea what the problem is.
I cant get any sense out of Vokera......Do you know if they have a service which will repair the fault for a maximum price like some of the other companies ??
I need an engineer who won't just give up & walk away.