I have a Gen 3 Thinkpad E14 (Ryzen 5 5500) with updated BIOS (8GB RAM and and 240 SSD) WIn10 PRO
I looked at the specs and saw that DDR4-3200 16GB non-ECC, CLL 22 was the spec and picked up the module from a local bricks and mortar for $40 CDN. GSKILL branded.
Followed the procedure and unplugged, opened up, disconnect battery, insert RAM, check it’s seated, Reconnect battery. Close up. power up. Got black screen. With power light continually on. Left it for 5 minutes thinking it’s memory training. No luck. Pushed power button. Turned it off and turned it back on and came up with the splash screen.
after a few trials I found that the computer would only boot up on the 2nd time of powering up. 1st time would black screen, 2nd time would boot as per normal. Did some forum hunting and tried a different brand same spec memory (Crucial). Instantly booted up. and works like normal.
Check forums for successful and unsuccessful brands of RAM as it seems like Lenovo is whitelisting even though the paper specs are the same.
If eventually it was booting with the GSKILL, then it’s not whitelisting, but probably just bad RAM.