Mitsubishi Heavy Idustries A/C Stopped

[sjbrewy]

HI,
My 8 yr. old MHI A/C SRK71ZEA-S only gets used about a week every summer for the last 8 yrs, so its not worn out, but today I put it on for the first time this year and after about 2/3 hours it stopped working and flicked the Circuit Breaker Switch off for this unit at the power box and wont start up and the indoor unit RUN light is solid on and the TIMER light flashes 6 times, meaning if I read Self Diagnosis Function page properly says under "Description of Trouble"-(Error of signal transmission) and Cause is- Defective power supply, Broken signal wire, defective in/outdoor unit boards.

So with this problem, does anyone know if there is a common fault problem with this unit, I checked the outside unit fuse and its not blown. So is it the PCB boards burned out or something.

I spent a bit more money back then getting this A/C as thought it would be more reliable and robust than others like my Fujitsu's that are same age and are still running good, so very disappointed.