HELP!!!!

I have a Hantarex Polo 25 inch CRT monitor, It keeps powering off after 10 minutes then I have to wait for another couple of hours before screen is ok again once rebooted.
I have downloaded the flow chart for the monitor and in there doesn't give me a rough idea.
I did speak to Hantarex themselves who are based in London and they said I need a new Chassis or a repair to the chassis.
I was wondering if anyone out there had a similar problem and what they did to resolve it.
Please help.