Wrong Region Cant get a foreign dvd to play, it says wrong region

Thank you, B. L. Kaplan, your advice worked on my PET710 (at least for dvds Region 1 and 2). I am a little worried though. A friend of mine told me some time ago that after he had changed his portable reg 2 Philips (not this model but a newer one) region free, it was OK for a couple of months but then he started to have problems (reg 1 dvds did not show well, sometimes any region dvds did not play etc.). Has anybody long-time experience of PET710 which has been modified? Thank you, B. L. Kaplan, your advice worked on my PET710 (at least for dvds Region 1 and 2). I am a little worried though. A friend of mine told me some time ago that after he had changed his portable reg 2 Philips (not this model but a newer one) region free, it was OK for a couple of months but then he started to have problems (reg 1 dvds did not show well, sometimes any region dvds did not play etc.). Has anybody long-time experience of PET710 which has been modified?