Instead of needing a mod chip, you could jam the internal open/close switch mechanism closed. Allowing you to open the disc tray while it was still spinning. You'd let a legitimate game boot up to pass the DRM, then swap in a burnt disc. I wondered if it contributed to the drives failing.
Also to your point, is Disc Rot itself attacking original discs.
>After recording, the CD-R disc satisfies the specifications as written in the chapter DISC SPECIFICATION of the Red Book.
Also it was common knowledge in the modder community that playing with a modchip burned the laser diode. The theory was the CD-Rs reflectivity made it overdrive. It could also be the modchip itself caused the laser to burnout. Most chips were soldered directly to the CDROM controller. And may have been inadvertently overdriving the laser.
I think burned discs are probably one factor but I think general hardware failure or dirty lenses are a more common cause.
All these disc swap techniques work the same. The PSX only authenticated discs on boot or after the cover was closed, the latter being easily defeated with a piece of tape. If you could swap an authentic disc for a burned one after it had been authenticated, but before any of the actual data had been read, the PSX would run it. The cheapest option was to just force the motor to stop spinning by hand and swap discs at the correct time in the boot process. Cheat discs/devices like the Gameshark made this process easier because they would spin the drive down once you reached their menu and were designed to launch another disc when commanded so you didn't have to precisely time the swap.
Ah, yes that's why I recall thinking doing the trick caused the disc drives to fail.