Clear CMOS by disconnecting power to the PSU, remove the CR2032 coin cell battery, hold in the power button for 30 seconds, consider replacing the $2 CR2032 battery with a brand new one. If your new GTX 1650 graphics card is not OEM Dell you may need to install your original Dell OEM graphics card, F12 into the pre-boot menu and disable Secure Boot. Then you can install your new 3rd party GTX 1650.
I have an XPS 8910.  I have upgraded the memory, monitor and hard-drives in the past.  I decided to upgrade the video card, from the NVIDIA GeForce GTX 730 to an NVIDIA GeForce GTX 1650.  I replaced the existing card with the new card, and when I tried turning the system back on nothing happened.  I have an RGB keyboard and that didn't light up.  The display said that there was no HDMI cable connected.  I could hear the hard-drive whirring but after about 60 seconds the computer shutdown.  So I then reopened the case and put the original card back in, thinking the system would return to normal.  Same result as with the new card.  The system wouldn't start up.  I've tried alternating between both cards a few times, making sure that the relevant card has clicked in place properly each time, but still the same result.  Is it possible that the new video card has damaged the mother board?  = Steve
XPS 8910, dead after GeForce GTX 1650 upgrade