Catalina and 3rd Party RAM late 2013 iMac

[Westcoastlib]

So after much effort yesterday I installed Catalina. I had to remove 3D party RAM added in June because of a conflict. After Catalina was up and running I reinstalled the RAM. Everything was fine. Then today it crashed. Ran diagnostics and got the same RAM errors I got during install. Computer currently hangs on 99% of progress bar so it won’t restart.

Any suggestions? I could remove the memory again and reboot, but Catalina without the memory is slllloooowww. Kind of at a loss here. And not a techie but not a Luddite either.

 

[FNH15]

Sounds like your RAM is the issue… What brand is it?

 

[Westcoastlib]

Crucial. Worked fine for 6 months prior to Catalina. Apple support wants me to bring the iMac on for repairs.

 

[FNH15]

Crucial. Worked fine for 6 months prior to Catalina. Apple support wants me to bring the iMac on for repairs.

You might consider contacting Crucial for a replacement under their lifetime warranty policy, just as a final step to rule out an issue with the RAM itself. That is weird, though...

 

[Westcoastlib]

Crucial doesn’t seem to honor it if through Amazon. $200 RAM.

 

[FNH15]

Crucial doesn’t seem to honor it if through Amazon. $200 RAM.

Do you have another machine to try it in? How much ram are you trying to run in it?

 

[Westcoastlib]

Unfortunately I don't, which is why I'm bringing it into the Apple Store this afternoon for a diagnostic. They can test the RAM on another machine. The truth is, the likelihood that the 3 8GB RAM that I installed six months ago (total 32GB RAM) and which worked flawlessly happened to fail miraculously at the exact time I installed Catalina seems rather remote to me. Occam's razor says it must be a Catalina (software) conflict.

 

[leventozler]

Are they 1.35V? I remember 1.5V RAMs may cause panic under load.

Important Info for 2013 iMac 1.35v VS 1.5v RAM Upgrades

Hey everyone, I recently took shipment of my BTO iMac and upgraded the RAM with Kingston HyperX pnp 1600mhz DDR3 RAM 1.5v. Everything was fine for around 2 hours and then all of a sudden, my machine shut down and I got a Kernel Panic. Booted back up, same thing shortly after. Three Kernel...

forums.macrumors.com

 

[Westcoastlib]

I believe they are the lesser. https://www.amazon.com/gp/product/B008LTBJFW/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1

I checked compatability fairly thoroughly before buying, and confimred they were compatible.

 

[leventozler]

I believe they are the lesser. https://www.amazon.com/gp/product/B008LTBJFW/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1

I checked compatability fairly thoroughly before buying, and confimred they were compatible.

Yep, seems low-power modules. You could also test them one-by-one to see if one of them is faulty. I also have the late 2013 with 32G ram and I didn't have any problems during setup or after.