It took probably 10 hours of troubleshooting going off his troubleshooting guide. There was a tiny short i couldn't even see through my jewelers loupe, but measurements said it was there. So, I scraped between a couple pins with my smallest tweezers, and boom. Done.
Then, after I finished, I discovered there is a newer and better version of this mod, the iFlash2PS2. The IDE Resurrector only supports up to 128GB cards. The iFlash can handle up to 1TB. And it looks like slightly less soldering. So, learn from me. Do the iFlash.
I'm assuming you all know about FMCB, and how to rip your discs to ISO files. If you don't, this is a great way to save your console that won't read discs anymore, like this one I picked up in an "as-is" bin super cheap at a used game store. I'd look up Tito from Macho Nacho's PS2 mod videos.
Here's a pic of my terrible wiring. Yes, that's from a CAT5 cable. The wire is ordered for this mod wasn't small enough and I was too impatient to wait for more. It's very ugly, but it works. You're going to want 30ga to do this right. CAT5 is 24ga, and it barely, barely fits. Honestly, if i get ambitious I might rewire it later. The SD slot wiring is way easier than the board soldering. You can't see it of course, but I know it's there. And I'll have to see it again when I eventually install a Retrogem.
Congrats on the finished project!
Thank you! Not having a convenient way to load games on the slim was the biggest reason it's been collecting dust for a couple years.