One repair shop guy said my used PSU was fine, another said replace it, who do I trust?
I had a 6 year old 650W unit from a friend's build, shop A in Phoenix tested it and said the rails are stable, but shop B in Mesa pointed at capacitor bulges and quoted $85 for a refurb, so which side do I lean on when my budget is literally $40 and I have a spare 450W brick in my closet?
That $85 refurb is basically them selling you a used unit with new caps, and you can't even afford it anyway. This whole situation reminds me of how people treat car maintenance, they'll trust the guy who says it's fine until the thing dies on the highway. You got a spare 450W brick sitting there, so just use that and save your $40 for something that actually matters.
Man, did you actually SEE those bulged caps yourself or is that just what shop B claimed? I'd want to pop the cover off and look before I trust either of them, cause that's a 30 second check even if you've never opened a PSU before. And what's the 450W brick from, a prebuilt or an old build of your own, cause those OEM units can be straight garbage too. If you're not running some power hungry GPU, that 450W might honestly outlive that 650W with fresh caps anyway.