So, I want to get a used PS1, but most sellers even IF they test it just see if it boots a game and consider that working. Are there any good ways once I get it to make sure everything is working? Any sort of app or something I can use to fully test the disk drive has no read issues, the controller ports, memory card ports, I/O ports, etc all work fine?
Try a few different games to see if there is any issue. Some game that you can quickly play FMV sequences throughout the disc would be helpful. You should also test a game with redbook audio or just a factory audio CD to see that audio in that format plays smoothly. Maybe also a game that uses XA audio like Mega Man X4 or Castlevania SotN. Testing the controller and memory card ports is easy enough. Use a 2 player game (Street Fighter or Mortal Kombat) to see if the controllers both work and use the built in memory card management to see if you can transfer files between memory cards. Chances are if the system boots a game and you don't notice anything wrong then it's probably ok but you might have disc reading issues that weren't observed. It could be as simple as needing to clean the lens or as bad as needing to replace the optical assembly or figure out what might be wrong with it. But booting a game is a start. Though some might consider that to mean different things. If you just wait to see the first screen of anything past the BIOS as booting the game that isn't very good. But if it makes it through all the logos and copyright or intro stuff to the main menu, that is pretty good. Though I don't understand why people can't spare the time to test play just a little bit.
Stay away from fat PS1s, I get boxes of 20-30 of them a month and I'm lucky if 20-30% of them don't have failing lasers even with last effort pot tweaking/lubrication etc. Even then if it works with retail discs; I mod these and they will struggle with burned discs. PSones are the better option since they were later in the consoles life and objectively have less hours of use. There's no way to tell, it's 20+ years old electronics, just open a case if it doesn't work. If you do plan on modding this I'd just pick one up from one of the sellers here who actually have tested them in-depth. eBay "testing" is booting a perfect condition disc to the title screen and putting up for sale I'm sure.
That's not really an option, as I want to use a PS-IO on it. I need one with a parallel port. I was specifically targeting SCPH-7501 models.
What do you need the laser for then? Very, very rarely does anything else stop working in my experience aside from the laser going out. I wouldn't even worry about it at all.
It will be a while until I can get a PS-IO as they are pretty heavily back-ordered for now, plus not all games are compatible and others worked by putting other disks in, such as Monster Hunter and Vib Ribbon. I wanted to still be able to play my disk games until I can switch over to a PS-IO.
As MottZilla suggested, try a few games and watch for long load times and FMV skipping. Also check if controller inputs work, as sometimes the protection fuse blows. Do a visual check on the connectors, especially the expansion port. You want shiny metal, if possible.
If your getting a psio then you don’t really need to worry much about the laser being in good condition. Your just running games off the sd card so it doesn’t matter. All you need to make sure is that the lid switch works for the psio that’s it.
