ThinkPad not booting with 1-3-3-1 beep error code

I’m experiencing a beep code error on my ThinkPad T440p.

I have checked the code error here: www.thinkwiki.org/…/Error_Codes_and_Beep_Codes

The code is 1 beep 3 beeps 3 beeps 1 beep. Suggested to be a RAM or RAM module issue.

The same RAM sticks work in my X220 no issue.

The issue started occurring after I attempted to update the CPU from an i5 to an i7. It is possible I forgot to remove the CMOS battery or Laptop battery when I did this. It was a few months ago, so I can’t remember for sure. I have since put the i5 back into the laptop.

I tried following the suggestions here: reddit.com/…/lenovo_thinkpad_t440p_bios_beepsq

Unfortunately they did not work. I don’t think the issue is a CMOS battery issue. I am thinking it may be a motherboard issue.

What happens when I try to boot it up, I get the 1-3-3-1 beep code. Nothing happens after that. The screen is blank and the power button is green.

Is it likely that the motherboard is dead? It’s the only thing I can think of, at this stage. Is there any other things I can do to test it? If I am confident enough that it is a motherboard issue, I may decide to get another motherboard. But I don’t want to spend the money when I am not absolutely certain, if that is the cause of the problem in this case.