Japanese Saturn locking up after playing Grandia w/ real disc

Got an odd problem. Have an unmodified Japanese Saturn that's had light use all it's life. A year back I beat Lunar MPEG edition on it and had zero issues while playing many extended gaming sessions. Also runs all my other Japanese games fine though I probably don't play most more than 30 minutes at a time.

Anyways, I started Grandia a couple months back and everything will be fine but after an hour or so of playing the game will randomly lock-up usually when the drive is trying to load data such as a character's voice for a magic move. It will also do this when loading going in / out of buildings. If I power off and back on immediately I will experience the same lockup after 1-3 battles. BUT if I power off and WAIT a few hours the game will again run fine.

Here is the kicker, I burned a backup of Grandia and did the swap trick for the first time ever just to see and the game didn't lock up at all! I loaded the same save and was able to play as long as I wanted without issues. Just to further test I even let the game run over 72 hours straight and then continued playing with no lockups! With the real disc like clockwork I can get it to freeze after only 1 hour of playing.

After this I suspected my disc may just be bad so I bought another legit copy of Grandia. Did the same test and again the game locks up after an hour.

When it does lock the music will still play fine and you can still hit the button to auto-battle so the text will appear but the game just sits there while everyone on the battlefield is frozen with no access to menu's. I've gotten used to saving often but this is a real pain when you are a couple battles away from your next save and the game does this wasting all the time you just played.

Any idea why the backup plays perfectly for as long as I want while both original discs cause the saturn to lock after an hour, yet work fine again if you power off and wait some time? The saturn only gets slightly warm to the touch and I have tried running a CD-Drive cleaner through it a few times.

 

Huh. Very odd. Have you tried a different Saturn or a different laser assembly?

 

It's a Hi-Saturn MMP-11 so I didn't really want to open it up. It's in mint condition with only light use.

I have a modded US Saturn but that won't boot the NTSC-J region disc. Never got an action replay as I had no use for it with the mod chip so I don't think there is a way for me to test it.

 

Might as well either get a new laser assembly or a new saturn. If that still doesnt work you may have some bad luck w/ those Grandia discs

 

As far as I know (and take that at face value, because I'm no Saturn expert), there aren't any incompatibility issues with the Hi-Saturn that would cause such a thing. My first instinct would be to say the discs are scratched, and that because newer optical drives have stronger lenses, it'd be pretty easy to read the disc and make a perfect copy on a newer, (arguably) better disc, hence why I backup works.

But it sounds almost too methodical for that, so my next guess would be the laser. It sounds like there is a part of the disc that it just can't quite hit, in which case, the laser needs tweaking or replacing.

If you're careful, the thing should still be somewhat mint condition after you open it up and check it out (plus it doesn't hurt to give it a good clean whilst you have it open - something that'd I'd do regardless of how minty fresh a console is).

 

Both copies of the game are scratch free so that isn't it . Given it's only Grandia giving me issues I'll probably just deal with it. Once the other games start giving me issues I'll open her up and take a look.