Sorry to keep replying to myself, but after a few tries, put the second channel of RAM back in, and it's back to POSTing with 8 gigs of RAM.

I should probably do a few hours of memtest86 at some point, but...

Good news, I guess - since I am not going to try to return this lovely PSU to the computer store, I don't think, I guess I am back where I should have been a week ago with a new PSU. Time to plug the SSD back in and see if Windows recognizes the new video card...

VivienM wrote on 2023-06-02, 04:59:

Sorry to keep replying to myself, but after a few tries, put the second channel of RAM back in, and it's back to POSTing with 8 gigs of RAM.

I should probably do a few hours of memtest86 at some point, but...

Good news, I guess - since I am not going to try to return this lovely PSU to the computer store, I don't think, I guess I am back where I should have been a week ago with a new PSU. Time to plug the SSD back in and see if Windows recognizes the new video card...

I don't understand You. You asked for help, in 2nd post, bogdanpaulb told You what to do, after few posts , shevalier told You the same thing, then I did the same, and finally SquallStrife also told You what to do. It is so simple (take the RAM out) that You could do that in a 15 seconds, but still, You resisted for almost a week. Now You telling here to everybody that this worked???? I'm so pi$$ed right now, it's better to keep my mouth shut!

No need to be PO'ed man, it's a learning process.

Glad you got there in the end OP.

Moral of the story is: assume nothing, test everything.

When you assume, you make an 'ass' out of 'u' and 'me'. Mostly u though. 😉