Kenwood UD70 'Protect' & Static noise?

I bought a replacement of Ebay for my UD70 which constantly flashed 'protect' when it was turned on. The graphic equiliser was the issue, when disconnected the system worked ok.
The replacement system was working fine for a week or two, but this now 'flashes 'protect' and now both systems have 'Static' noise crackling quite loud which if I get them to work without the protection kicking in the music can't be listened to because of the background static noise.
I am interested in knowing if anyone has the same issues and how you solved them. I've read the responses and it's not the speakers. How do I go about mending the units using the output i/c from FULLERS?
Many thanks
K. Murphy