Replacement CPU fan.
https://www.amazon.com/StarTech-com-60x10mm-Replacement-Computer-Connector/dp/B00006HOMA

Replacement power supply. Noisy fan could be either power supply fan or CPU fan. Given the age of the PC, both should be replaced.
https://ebay.us/m/vjCLCD

Rollover switches need replacement.

Qty 4
Part# A-17813

https://www.marcospecialties.com/pinball-parts/5647-12693-19

Pinball 2000 Software Updater
https://mypinballs.com/software/pinball2000/software_updater.jsp

BR2325 battery for PRISM card

https://ebay.us/m/nrg2FS
StarTech R232 Serial to USB Null Modem Adapter cable needed to upgrade game code to latest version