XPS 8930, won't boot to C: SSD?

What color is PC's power button, and steady or blinking, when it won't boot? If blinking, count the blinks and look up the error code here. 

Did you, or SupportAssist ,or Windows Update install a BIOS update right before this problem started?

Have you disconnected all external USB devices (printers, scanners, etc) and tried to boot with only mouse, monitor, keyboard connected? And make sure monitor is connected the add-in video card, if you have one, and not to either of the onboard Intel Graphics ports.

When was last time you replaced the motherboard battery? A weak/dead battery can cause all kinds of odd symptoms. If nothing else, you'll rule the battery out.

1. Reboot and start tapping F2 when you see the Dell splash screen to open BIOS setup
2. Copy down all current BIOS settings, to be safe
3. Power off, unplug power cord from rear of PC
4. Press/hold power button for ~15 sec
5. Open case and remove motherboard battery (check Service Manual for details)
6. Press/hold power button for ~30 sec
7. Install fresh CR2032 3-volt coin cell battery
8. Close up and connect mouse, monitor and keyboard
9. Reboot
10. Tap F2 when you see the Dell splash screen and make sure the NVME SSD is correctly detected in BIOS and Windows Boot Manager is first in the boot sequence.

@RoHe​ Thank you.  I will try all this tomorrow.  Too tired tonight.  I will keep you posted as to what happens.

F2 into BIOS, reset to defaults or make sure UEFI (Legacy mode disabled) is on with Secure Boot enabled. Reboot. If OS doesn't load and/or Win RE is unable to repair startup, the drive is probably not formatted for UEFI/Secure Boot (GPT file format) or, more likely, somehow the boot partition got messed up when adding/removing drives. Easiest way to resolve is recovering files you want from the drive on another computer as a secondary drive, then reinstalling Windows from USB or Supportassist Pre-boot after ensuring BIOS is set to default with UEFI/Secure Boot enabled.

You might also be able to browse and select the proper UEFI boot image from BIOS boot options, would need to google it but something like Firmware.efi in one of the drive partitions.

@RoHe​ I have only the keyboard, mouse, router, and monitor plugged in and it booted to the sign in screen.  I got this message "Your PIN is no longer available due to a change to the security settings on this device.  Click to set up your  pin again."  I tried that but it did not work and gave me the option to use the hotmail account login.  The problem is my husband does not remember his hotmail account password.  He hasn't used it in years.    I have not changed any security settings so no clue why it de-activated the pin.  Is there a work around for this?  

I also got no blinking with the power button.  I think the problem is one of the many things plugged in the back.  My husband is not very tech savvy. 

@RoHe​ Okay I managed to find the lost login password and logged in.  I tried to set up a new PIN  but for some reason that did not work and it keeps saying the same message about changing the security settings.  I am okay with logging in with a password.  

Now I have a new problem, when I try to shut down it keeps coming back to the login screen and does not shut down.  I have to crash it by holding the power button on.  

Any suggestions on how to fix this?

@ErnieHutch  - Did you replace the motherboard battery? You should do that before any further troubleshooting... 

@RoHe​ No I haven't replaced the battery.  Could that cause it to not shut down?

@RoHe​  I will replace the battery later tonight.  I would have thought the battery would have lasted longer.  My HP desktop is 14 years old and I have never replaced the battery.

Like I said, a weak/dead battery can cause all kinds of odd symptoms. And even if a new one doesn't help, you've ruled it out for only ~$3 - $4. 

PC's use more battery power these days, and batteries are "cheap" even though they cost more to buy.  Typically only lasting ~3-4 years nowadays.

@RoHe​  Hi Ron

The computer has been humming along nicely since I was here last.  Now last night it would not boot again.  So I followed your instructions and put in a new motherboard battery and rebooted fixed the time and all in the bios is as it should be.  It still won't boot and I noticed the power supply fan is not working.  It powers up and the green light is on on the back of the power supply but the fan is not working at all.  Would this be the reason that it won't boot to windows?  I can boot to the bios no problems.  Hoping you can help me again.

Do you see the Dell splash screen when it won't boot? Do you get any error messages?  What color is PC's power button, and steady or blinking when it won't boot? Count the blinks because that's an error code.

The XPS 8930 PSU fan only spins as needed, not all the time, so not running when you boot now doesn't tell you anything.  Run the PSU BIST using the instructions for a PC with PSU test button.

Assuming PSU passes the BIST, reboot and tap F12. When the menu opens, select option to run diagnostics and run all of them. Copy error messages, if any. This can take a long time so be patient and let it finish...

BTW: if you're using a power strip and/or surge protector, remove those and connect PC directly to a known-good outlet.

@RoHe​ Hi Ron, I performed the BIST test and the green light comes on for a second only and the fan does not spin.  It tries but fails.  I have ordered a new power supply and it will be here tomorrow.  Hopefully that will solve the problem.

I do get the dell splash screen but no error messages.  The power button is white but does not blink.  After I put in the new power supply I will get back and let you know if it worked or not.

Many thanks again for your help.

@RoHe​ Hi Ron,  I just finished installing the new PSU and it is all working now, thank goodness.  The fan used to make a lot of noise and I am wondering now if this has been the source of all the problems.  So now we have a new battery, new PSU and hopefully it will hum away for a few more years.  I got this PSU on Amazon and I think the price was pretty good.  https://www.amazon.com/dp/B0CMWCSK56?psc=1&ref=ppx_yo2ov_dt_b_product_details 

Many thanks again for you help.  You have been amazing.

@RoHe​ How do I mark this whole thread as solved?  Well  solved for now LOL.