My IIci's socket with metal clips has gotten really loose because of all the testing I did of the SIMMs when I was selling them, so they too can go bad. In my case it's probably just from constantly inserting/removing. I believe the parts are rated for only so many insertions.
I went back to my original Downtown Doug Brown 2MB SIMM and it's solid again. Doug used a thicker PCB stock that's apparently not common anymore.
Yep, and it was purely by accident, haha! When I first did the project with the 2 MB SIMMs, it was the first time I ever designed a PCB. I ordered the boards from Seeed Studio and they were more like 1.3mm instead of 1.2mm, even though I specifically ordered 1.2mm because it was the closest they had. Heck, I don't think I even knew the correct thickness was 1.27mm at that time. I thought it was odd they were thicker than I asked for, but they fit snugly in the sockets just fine and I was happy. I had no idea what was about to come after that point with everything being too thin. I wonder if they were still making them as 1.27mm at that time, or if I got lucky with tolerances, or what.
Then, when I designed and ordered the 8 MB version, and other stuff like the IIfx RAM, those PCBs were actually 1.2mm. I didn't notice any problems with my testing, but a bunch of SE/30 users ran into issues. Adding solder to the SIMM contacts can help, but it's difficult to add a thin layer evenly, and I would guess that if you make it too thick it'll damage your socket.
Every time I've tried to order 1.2mm PCBs since then, I have never been able to hit the jackpot like I originally did. They're always right around 1.2mm. I believe BMOW eventually found a vendor that can do a special process to make them slightly thicker, so his more modern SIMMs are better.
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