XPS 13 9310 - no bios and unable to start with usb either

You can perform an RTC reset.  With the system is power-off and connecting to AC power.  Press and hold the power button for 25 seconds.  The system RTC reset occurs after you release the power button.

Does the system boot with error message to adjust date and time? 

thank u,  it does restart and gets dell logo back and it stays on dell logo for ever. no errors. light stays white on. what else can i try please?

@Chino de Oro​ i do not think there is any progress from earlier condition. its 9310, ***private info removed from public view***. i do not know what bios it was but it was the original laptop came with. i have tried usb with an adapter and usbc, formatted as fat32 and using usbc near the power button, and then also tried the left hand side usbc. and using internal keyboard/screen. do u think i should be trying it with an external keyboard? i did 'd' test and screen goes thru colour test and then ends up with dell logo. i also tried to remove ssd and it does not behave any diff.  thank u very much for trying to help!

Do not post system service tag or any other private information on this public forum.  While it's dinner time at Christmas Island, it's quite late in Kingston.  Can always attempt again tomorrow.

To prepare for BIOS recovery, make sure the battery is charged and connected.  Can not use external keyboard for recovery process.  Download and put this BIOS recovery image file onto a blank USB with FAT32 formatted, preferably 8GB or less.

Disconnect power adapter from the laptop.  Connect the USB to one of USB port.  Press and hold Ctrl + Esc key with one hand and connecting power adapter to the laptop with other hand.  Notice if the keyboard light lights up, release the Ctrl + Esc key and the BIOS recovery menu should displayed.  Select Recover BIOS and the process will start.

If recovery screen does not start, disconnect power adapter and restart the process again with hold combination key Ctrl + Esc then introducing power to the laptop by connecting the power.  On certain system, it takes several attempts to trigger the BIOS recovery menu screen.

After a few attempts and nothing, you can remove power and disconnect battery.  Discharge flea power and remove the boot drive.  Reconnecting everything and perform recovery without the boot drive.

@Chino de Oro​ thank you! but i have tried this dozens of times now with and without ssd, all i get is dell logo and white light on. any other tricks please?

There is no other tricks.  Just the process provided by Dell for BIOS recovery if the firmware got corrupted.  Besides the storage drive, not much of any other components in this system are removeable for testing.

@Chino de Oro​ thank you for trying!

The hard part is no LED blinks codes to identify the issue.  Solid white light is just indication of power adapter is connected and battery has power.  Status light would help with troubleshooting, yet nothing.

https://www.dell.com/support/manuals/en-us/xps-13-9310-laptop/xps-13-9310-service-manual/system-diagnostic-lights?guid=guid-100544e8-6b7c-4da1-b749-7bcced1d8ca5&lang=en-us