Problems with my Precision 3660 and ASUS RTX 3090

The LED error codes indicates memory DIMM power rail failure.   

@Chino de Oro​ 

Any idea about how can be solved?

Replacing the main board, the memory, the GPU or even the main processor is not solving it?

I have installed the ASUS RTX 3090 TUF and 4x32GB Sabrent UDIMM ddr5 

If you install the OEM components back and the error going away, that will indicate your upgrade components are having issue.  You can introduce the upgrade components back, one at a time, you will find out which one is causing the issue.

Could it be underpower?  What is the wattage of power supply you have?

The 3660 comes with 300w, 500w, and 1000w PSU's.  To power the 350w RTX 3090, the 1000w PSU is recommended.  I'm also attaching the spec sheet.  It has a list of compatible GPU's.

Thanks a lot to @Chino de Oro and @bradthetechnut 

The PSU is the 1000W one.

I made a test running windows 11 on a USB and in this case the 3090 was correctly detected and drivers loaded, so I presume the problem comes from the ubuntu 22.04 but it was running in my computer for 6 months before stopping.....

I'm at a loss then if the 3090 worked well on Win11.  I'm not familiar with Ubuntu.