Detection error 2100 HDD0 not accessible

[CometCKO]

I've owned my X61 for 10 years. Yesterday it would not boot and gave me a detection error 2100.
I vaguely remembered getting this message when my original hard drive died, but now it is on its second SSD, a 500GB Samsung EVO. I still had the previous smaller SSD, so I put that in the drive bay, but still had no joy recofnizing any drive in HDD0. I tried booting with a USB stick and that worked. Tried the EVO SSD in an external USB enclosure and it would boot fine from that (I run Linux Peppermint). I concluded that this time, it was not the drive, but the computer that was failing.

I concluded that the problem was in the SATA port itself. In researching the problem, I read multiple reports of SATA cables coming adrift, or the solder joints on the SATA connection failing. There was also a bad period when Lenovo was having driver conflict issues, but not relevant to my case.

I opened up the case to inspect connections, and decided to try the non-invasive cure first. I used a contact enhancer fluid (Stabil) applied with a small cotton swap to the SATA connector copper terminals, and again to the SSD terminals too. Upon reassembly, it worked! I'm not certain if it will continue to reliably boot, but hopefully this will help someone else who struggles with this error.