PAL DVD on JAP PS2

I have a JAP PS2 (SCHP 15000) with Modchip.com original chip that plays Jap backups and PAL backups (patched) perfectly via swap trick.

But a PAL DVD won't play. I get a Jap message prefixed "TV". Anyone got any ideas please?

I thought Japan/UK = Region 2 so no big problem expected.

Cheers