Strange Sega Saturn CD Drive behavior

[ChronoLe]

I have a NTSC Model 2 VA8 Saturn that is exhibiting some strange behavior when attempting to read a disc. When I close the lid on the cd reader screen, the Saturn will recognize the door as closed and attempt to read the disc. The disc spins, and the laser engages once (does not move up or down the rail), but then the swirling loading image freezes or stutters, like it is going in super slow motion. I'm hoping someone has encountered this issue before I recap the unit.

I have already ruled out the following, as I have swapped in working parts from another unit with no improvements:

1. CD assembly/laser
2. Ribbon cable
3. Bios chip
4. Power Supply
5. I reflowed the vram chips and several other chips on the board (SH-2, SCU, CD Control chip, ribbon cable pin connector), but unable to verify with my skillset/tools if the chips are faulty
6. I don't believe this is a vdp1/2 issue, as all the animations display properly on boot up

I'm not opposed to the recap, but would like to know if anyone has come across this issue before going forward.

Other strange behavior that I believe is related to the cd drive freeze issue:

1. Action replay will not boot, system will go straight to cd reader screen
1.5 However, the system will still recognize an official memory card with the ability to transfer saves to the system

The optical lens seems to operate fine with no disc in the system, lens will move up and down and system will state drive empty (no freezing). The freezing/slowdown only occurs when disc is present. Also, when the freezing is occurring, once the lid is opened, the animations return to normal.

 

[Jtretheway16]

Just wondering if you ever found a solution to your problem. I don't have the same model as yours, but I'm having a similar problem.

 

[ChronoLe]

Just wondering if you ever found a solution to your problem. I don't have the same model as yours, but I'm having a similar problem.

I solved a part of the problem, but not fully resolved. There were some pins in the cartridge slot that had gotten smushed together creating some kind of short. Once I was able to dislodge them from each other, the freezing/slowdown on the main menu went away. I do believe there is another issue related to the cart slot though, as once I got a game booted, there is some slowdown and graphic glitches.

Long story short, if you have some strange slowdown behavior, check the cart slot pins. Secondary to that, you can check the pins on the motherboard side of the cd connector, I've fixed systems that had some broken traces due to rust and corrosion.

 

[Jtretheway16]

Hmmm, very interesting. I'll definitely give a closer look at the pins. Thanks.

 

[ChronoLe]

Hmmm, very interesting. I'll definitely give a closer look at the pins. Thanks.

No problem. Please keep us in the loop with any progress you make. What you find may be helpful to others down the road 🙂

Also, can you describe some of the symptoms your system is having? I know you mentioned similar issues, but I'm curious how exactly it is behaving. Thanks!