I updated the Ram from 8 GB to 12 GB. Put it back together. It acted fine for a couple of minutes, then black screen and I cant even shut it off?

It is not clear, is that device now starting correctly after you reconnected the charger or is it still on a black screen?

If not, if you remove the new RAM you have added, does the device then start correctly?

The behavior described (black screen after a few minutes, difficulty powering off, then apparently working again after charging) points to a hardware/power or RAM seating issue rather than a Windows 11 software problem.

Use these steps to narrow it down:

1. Check power and battery first
   • Make sure the charger is firmly connected to both the laptop and wall outlet.
   • Let the laptop charge for at least 30–60 minutes, then try to start it again.
   • A weak or failing battery can cause sudden black screens that look like crashes.
2. Reseat the new RAM
   • Power the laptop off and disconnect the charger.
   • If the battery is removable, remove it as well.
   • Open the RAM compartment again and carefully remove and reinsert the new RAM module(s) until the latches click into place.
   • If the laptop has two slots and you added a second module, test with only one module at a time (first the original, then the new one) to see if one stick causes the black screen.
3. Check for blank-screen symptoms in Windows
   Once the machine boots into Windows and appears to be running:
   • If the screen goes black but the laptop is still on (fans/keyboard lights on), try:
     • Press Windows + Ctrl + Shift + B to reset the graphics driver.
     • Press Windows + P, tap P again, then Enter to cycle display modes in case Windows is sending output to a non‑existent display.
     • Press Ctrl + Alt + Del; if the security screen appears, open Task Manager and restart Windows Explorer.
4. Force a shutdown when it hangs
   • If the system is completely unresponsive and the power button does nothing briefly, hold the power button down for about 20 seconds to force a shutdown. Then wait a few seconds and power it back on.
5. If problems continue
   • If the laptop only misbehaves when the new RAM is installed (and works normally with the original RAM only), the new module may be incompatible or defective.
   • If it still black‑screens even with only the original RAM, there may be a deeper hardware issue (battery, motherboard, or GPU), and professional service is recommended.

References:

• Troubleshooting blank screens in Windows