Elitepad 1000 G2 - Hard Disk (3F0). Reboots on memory test, or when booting OS installation on USB

[DarthVega]

I bought a bunch of tablets from eBay and have been completing repairs on them. One of them was this HP Elitepad 1000 G2. It comes with the official Jacket that has 2 x USB slots, 1x SD cards slot and a HDMI slot.

I bought an official USB car charger online and was able to boot it up, but only to meet with a screen advising me the age old:

"Boot Device not found

Please Install an operating system on your hard disk

Hard Disk (3F0)"

I attempted to go into Recovery mode, but that just takes me to another error screen stating 

"BIOS Application Error (501)"

I went into the BIOS, disabled the Secure Boot, but was met with the HDD 3F0 error code. I factory reset the bios but again was met with the same 3F0 error code.

So I downloaded the HP Diagnostic tool and made a bootable USB. 

I tested everything and almost everything passed. Except for the HDD component test as that came up failed stating there was no HDD installed. 

But the test that kept failing (forcing an auto reboot, 2 seconds into the test) was the memory test.

I tried the Symptoms tests, every test the Diagnostic tool has on offer, but in the end the memory test keeps resetting the unit.

While I fear it is likely a faulty memory issue, I thought I'd try a bootable USB with an OS (windows 8 32bit) installation on it. The OS loads to the spinning dots screen (under the HP logo), but after it looks like it's about to load the OS installation screen, it resets again.

Admittedly, I believe it could also be a lack of power doing it, as I've plugged the USB charger into a mobile charging plug... and I accept any ridicule that comes my way for that.

But does anyone have any other suggestions?