First of all do the usual things of turning the unit off at the mains or unplugging it. Leave it for a few minutes before plugging back in to clear any volatile memory that may be causing the problem. It would be worthwhile replacing the batteries in your remote control as well.
If that has not worked, do you get a signal to your television or is it stuck in boot-up mode? I do not know these units but the Humax satellite boxes can freeze halfway through bootup because of a faulty capacitor in the power supply. To be honest, I have not heard of problems with the Pace made hardware, only the Philips written software although the MD of Pace did mention they sometimes had problems with component suppliers when he was interviewed on radio some time ago.
There are specialised forums on other sites for Philips PVRs where you may get more help but I think it may be time to contact Philips for support. IF it is a hardware problem caused by a faulty or poorly chosen component, you are covered for up to 6 years under the Sale of Goods Act rather than the one or two years that a guarantee may suggest. You would however have to show that a maunfacturing fault rather than wear and tear was the problem.