NTSC-US - SCPH1001 Playstation Reading Japanese Games

In Forum: Hardware Support and Discussion
By User: MotoXpro

I just recently picked up a boxed SCPH1001 PlayStation. I randomly tested one of my Japanese games in it as was surprised to find out it booted and played. I didn't think they could without modification so I opened it to look for a mod chip, but there was none to be found. Are some SCPH1001 PlayStations region free?, Any known manufacturing defects to allow that? Just curious thank you.

http://www.betaarchive.com/imageupload/2012-12/1354830323.th.83579.jpg

http://www.betaarchive.com/imageupload/2012-12/1354830381.th.44492.jpg

http://www.betaarchive.com/imageupload/2012-12/1354830397.th.67969.jpg