How do unlink my 401k from a cash account?

I don't really know how to explain this, but I will try. I had some issues with a checking account all of a sudden (when I go into the account details, the online services tab was missing) so finally I just created a new checking account, connected to online services, and it works fine. I kept the old one there too with a 0 balance just for the historical transactions.

On a second note, I have a 401k account and it sort of became a mess. I used to have my paycheck itemized and add the contributions to that account but it stopped working one day. I chatted with Quicken and they determined that file was corrupt (the paycheck deposit stopped working) so I finally just started entering my paycheck as net pay and not worry about tracking the details and contributions to the 401k.

So, I noticed I have like a $16,000 cash balance in the 401k account and I can't get rid of that because it says it is linked to a cash account. I finally figured out somehow that it appears to be linked to that old checking account that I had to remake, so I think that $16k is from the contributions that I used to have it enter from my paycheck.

If that is not too confusing and you understand it, what can I do? I guess I need to get rid of that $16k from the 401k somehow but I can't. Is there someway to unlink it or anything?