FileForums - DVD KEY 2.5 : Originals DVD doesn't work !

Hi everybody !

I have a PS2 Euro V4 (Bios with Gap), an Action Replay V2.01 and a DVD KEY 2.5 modchip who was installed by a professional !

I can boot all CD-R games but when I start in "Original Mode" with an original DVD Movie or Game the PS2 doesn't want to boot, even with the DVD Player of the Action Replay ! Before all DVD works fine ! (I put the DVD in the tray before turn on the PS2)

So as I know how to proceed, I opened the PS2 to check the work of the guy and all was good. I tested that all 5 points between the board and the modchip with a Clamp on meter tester HIOKI and all is ok !

http://www.hioki.co.jp/eng/product/field-c/328010s.html

I read on the forum also to check that the DVD drive is clean inside, so I opened it and it is not durty eaven the laser and I tried a Vertical position of the PS2 too !!!

Could you help me because I don't know what to do ?
I suspect the modchip "PS2 DVD" on the small board to be out of order !
I can only read that on the modchip on the small board "PS2 DVD". Could you tell me which company made it ?
Is it possible to change this modchip on the small board or to test it ?

Thanks in advance for your answer ;) ;) ;)

PS : For the information my nephew has exactly the same PS2 and modchip and DVD boot normaly !