Saturn plays 2 out of my 12 games

[retrobish15]

Hi. I have 2 sega saturns that I got off ebay. Both were listed as non working/not tested. saturn A had a bad laser and saturn B had this other issue. Saturn B would read the games no problem and then load them (I tested it with a real copy of all star hockey) the sega license screen would show, then the SEGA sports logo would show, then it would stay black and the disk keeps spinning. I then took the laser (whole assembly) out from saturn B and put it into saturn A and it worked perfectly. I even flashed an action replay cart with pseudo saturn and saturn A was able to play all the burned games I threw at it (North american and international). When I put all the lasers back in their homes and tried to boot some of the burned games I had on the Saturn B with the pseudo saturn cart in it, only 2/12 games fully booted. Policenauts and Galactic Attack. I really dont think it is a laser issue because I tested out the laser and it works fine and then I bought two new lasers for them and installed them. Saturn A works flawlessly with the new laser but saturn B still does the same thing. it does read and boot games but stops after the sega licence screen. What else could be wrong with it. Maybe a crystal oscillator is not working, or is it in need of a recap? or maybe something else?

Just for reference saturn A is a VA SD and saturn B is VA7 both ntsc north american

[zyrobs]

The CD Drive between those two models are not compatible. One of the pins on the ribbon sends a different signal, interfering with loading.

The optical pickup can be switched, but they need to be calibrated on a per-drive basis. Also, the height of the tray may be too high or too low.

[retrobish15]

Thank you for the response. I am not sure if the laser compatibility you mentioned is correct. In my post I mentioned that I switched out the whole laser assembly from Saturn B to A (VA7 to VA SD. both are 21 pin) and the Saturn VA SD with the VA7 laser assembly in it worked perfectly without any issues. This means that the laser from Saturn VA7 is in working order. I have since put new laser eyes in both Saturns and VA SD works perfectly with some minor adjustments and the Saturn VA7 is having the exact same problems as before (reads game, boots to saturn license screan, boots to SEGA sports screen, then nothing) I am wondering if a recap will solve this issue. 

[zyrobs]

hmm, putting the VA7 cd drive into the VA SD might work as long as it is a VA5 unit (VA SD can be VA3 or VA5), since the changed pin in question is the access led and the VA5 units have the access led removed, so there's no conflict. But the other way around likely wouldn't work since the VA SD drive would send access led signal down where the VA7 unit expects a clock signal.

Switching the entire cd drive is not the same as switching the optical pickup, and the pickup needs to be calibrated on a per-drive basis. If you still have problems despite getting a new laser, then one possible issue can be the drive tray being too high or too low. It's also possible there's some other fault on the drive itself though.

[retrobish15]

Okay that makes sense. So I think then the issue is something else. With the new laser in the VA7 (side note: I do believe my SD is VA5) I calibrated it and the drive to do the same thing as it did before any changes were made to the original unit (original to when I got it) and it can only boot 2 of my games fully and none of the others. Once I recap it all then I can at least rule that out. I bought a kit to recap the main board, disk drive board, and the power supply. If the issue persists than maybe it is a whole other issue. Thank you for you help. 

[retrobish15]

Hello. So I have done a full recap of the VA7 and the exact same thing is happening. Its like it can fully read games but at some point, something is not telling the machine to load further. the disk just sits there spinning and the laser isnt trying to read it, the laser remains dormant. I find it strange it will read and play policenauts (burned disk) no problem but not all my other games. could it be the way the game is coded and somehow this game bypasses the problem?

[zyrobs]

I'd try to realign the tray, and also use a multimeter to properly calibrate the laser (there's a guide on youtube on which point you have to measure to get the best alignment).

[retrobish15]

Its not the laser. I have literally took the whole laser board out and put it in a different Saturn and it works perfectly. there is also a brand new laser eye as well.

[zyrobs]

If the tray is out of alignment then the lasers focus point is too close or too far, making it impossible for it to see things even when it would work fine otherwise.

[retrobish15]

And I get that and that is what I did initially  in order to get the laser working in my other saturn. Its not the laser assembly. its in full working order. I truly believe it has something to do with one of the chips because its not telling the machine to continue booting and searching. it literally just spins until you turn it off. laser assembly works in my other saturn.