Erratic modchip behavior

I recently installed a modchip in a friend's Saturn (32 pin CDU IC, 21 pin ribbon cable, case revision 2) and it behaves somewhat odd. Some copied games will boot right up while others don't boot or are recognized as audio CDs. What's weird is that the with those games that don't boot at all, the drive tries to do the security ring check (and fails of course), and yet no attempt to do that is made on games that work fine.

I imagine that either there's a problem with the CD unit's laser or the modchip has the jumper set the wrong way. Maybe both. If I have to adjust the laser with that little potentiometer on the CD board, how far left or right should I turn it?


P.S. The chip was purchased from Lan-Kwei, if that matters (which I hear it might).
Before you begin messing with the mod chip, I have to ask - what makes you so sure that ALL of your copied CDs are burned correctly? Any of the issues you described can be (and usually are) caused by incorrect burns - in particular, games set to the wrong country code, or games burned without a correct postgap after the data track (they will be recognized as audio CDs).

If you're experiencing your troubles only with certain burned CDs but never with the rest, then that should rule out the modchip itself as the cause.
All my games are burned just fine; I've been playing them on my own Saturn using the swap trick with absolutely no problems. All country codes and gap settings are 100% correct. It couldn't be a problem with the media used because (although many different brands of CDR are used) the non-working games aren't confined to any particular brand (or brands).

I have a couple of HK silvers laying around- I'll test those and see what happens.

It could be just a dry solder joint on the mod board, or with your soldering. Perhaps the power wire is not adequately connected.
I've checked the connections; if any of them were loose nothing would work at all. I'd wind up at the CD browser screen with oddly shaped spheres floating about if anything wasn't connected right.

Is the problem constant? For example, do the games you have problems with always fail to boot or only some of the time?

Another thing to consider might be that the connectors on the mod board might be dirty. Give 'em a clean and see if this fixes your problem...
Originally posted by Curtis@Dec. 15 2002, 5:02 am

Is the problem constant? For example, do the games you have problems with always fail to boot or only some of the time?

Right. Some games just won't boot; although they work perfectly on other Saturns via the swap trick.

Another thing to consider might be that the connectors on the mod board might be dirty. Give 'em a clean and see if this fixes your problem...

I went over the connector with Q-tips and rubbing alcohol. No result.


games that not working with modboards but boot up with the swap trick...

Try inserting the cd-r's on your pc's cd-rom, and with cdrwin, do a sector check, and read the first sector (sector 000000), does the usual sega header shows up?? if yes, well, It must be some hardware problem, if it doesn't the cd is badly burned, and what happens is that when you swap (saturn still recognizes it has being a saturn cd, as the country codes are checked immediatly after the protection), and so, when u do the 2nd swap (original->cd-r) saturn reads the country codes (ip.bin actually) from the original, because u can't swap that fast, as saturn reads it in a hurry... And when u use the modboard the header isn't there....

well, to much explanation for a possible thing... better wait for the answer first...
I'd suggest that the modded Saturn has some hardware issues then. Possibly the laser is dirty and just needs a clean, or perhaps it simply doesn't like some of the media used. I know it's a pain, but if possible reburn one of the non-working games at 1x to see if this helps any.
I was just going to lead you down the way of the CD drive's laser lens as well. In fact, the whole problem sounds like you have a "borderline" laser, meaning one that's just about barely able to read some games and just about fails to manage to read the others - at least the data portion, at 2x speed. (I fail to recall whether you mentioned anything about being able to play the audio tracks on your non-playable game CDs or not.)

Anyway, my point is all you may need to do is increase the laser's strength just a little bit. Refer to the CDRW FAQ in the Misc. section, it explains how to increase the laser's power to enable the Saturn to read (less reflective) CDRW discs; obviously that's not your goal but a slight increase could solve your problem.

Keep us informed...
I got off of my lazy ass and re-burned one of the stubborn games at a slower speed with rousing success. It works! Thanks, everyone!

Taelon: I suspected as much. I'll be sure to read the CDRW FAQ and give the adjustments a try. I have at least one CDRW on hand to test it with, but getting the other games working is the primary goal.

It would also appear that games will boot if the machine is started up with the disc already in the drive, but they won't work if launched from the CD browser screen. Is this a flaw in the modchip I'm going to have to live with, or should I try messing with the 0014/0019 jumper?