The crystal is the tin can looking component in the middle of the PCB. 
It’s a Crystal Oscilator, used for the cpu to have a constant clock (tick-tock), some integrated circuits have their own but this pad doesn’t (?)
Its common to see a standalone crystal on many PCBs. Depending on the encoder chip under that epoxy blob, it actually not surprising that it lacks a Crystal Oscillator.
You can still find a quartz crystal oscillator on modern motherboards as the quartz can only get so small and there not enough room on the CPU. On modern motherboards the Oscillator is part of the front side bus, and a multiplier increases the cycles for the CPU clock.
The Crystal Oscillator is usually quartz crystal, hence why you see time pieces claim quarts movement as quartz have a very steady and regular oscillation which makes it good for clocks and for CPUs to keep their clock cycles.
I got a retrolink Saturn pad
Guess what? It’s already broken lol
How do I mod this into a normal Saturn pad? Is it as easy as switching PCB’s?
The right plastic tab broke off. To press right on the pad. I’ve had the pad 1 week.
So I took an old Fuse, snapped off the metal prongs, then used black tape to tape it to the cross, and IT WORKED hahaha. Wow.
Anyways… is this PCB not the right size for a stick Saturn pad? It looks like it is…
Thats why I avoid Retrolink
Don’t. Get them! You’re paying 10$ for a PCB. It swaps right into a real, 100% legit Saturn pad with no trouble.
Well, unless you care about the shoulders, those are the only things that don’t work. I don’t care, I never needed or used them. I’m sure there is a way to mod those to work with a little tinkering maybe.
As far as I’m concerned, the SLS is officially obsolete and unnecessary as again, you can take a retrolink PCB And stick it right into a normal, official Saturn US pad and it works, minus shoulders. BOOM a USB official Sega Saturn pad!