Dell Inspiron 15 5000 series wont boot or boot any media

I am a computer technician working out of a local shop and we had this laptop come in with a perplexing issue. I will go ahead and run down what I've tried.

Bios: Tried disabling secure boot, enabling legacy boot and legacy options. After such I tried loading both Windows 10 DVD as well as a bued Windows 10 ISO on USB flash drive (Tried both Windows creation tool and rufus).

Both USB and DVD media go to a screen with Dell logo and circle dots loading symbol. Looks like the CPU light gets active for a bit and then just stops. Everything stays loading for infinite time. It did this before I changed settings in bios as well.

Three restarts: Tried doing three restarts in a row to launch the troubleshooting screen. It would just go to "Preparing Automatic Repair" and stay there for a long time.. over night even.

Then I tried setting everything back to defaults and trying to just boot the hard drive. Secure boot enabled, UEFI set, default keys in place. Now on each start I get either: 1. Dell logo with swirling dots. 2. Dell Logo with Preparing Automatic Repair.

Tried chkdsk on existing hard drive. Tried diagnostic for hardware: 100% pass. Tried Dell Restore & Backup: Infinite loading screen.

Is the BIOS borked? I've been working on this for a solid week to no avail. Going a little crazy.

Any input on this would be greatly appreciated. I really have no idea where to go from here as I've scoured the inteet and have tried every troubleshooting concept I've leaed in the past 10 years.

**I also tried static discharge, removing battery and AC and holding power for 60 seconds. Also updated Bios to one newer iteration supporting Windows 10.