I have installed my new printer 4 days ago, printed the test page and a couple of documents (all good). Then powered it down and now it won't power back up! It switches on ('Please wait..' in the display), then within about 30 sec it switches back off. Then a few moments later switches on again,(please wait) then switches off again - repeating this process endlessly.. I have tried powering down for 5 sec with the on/off button, I have tried unplugging and plugging back in, nothing works!! Please help!! I need the printer desperately as the old one had died (and this is the replacement for my business!!).