1st trust deed question

[Robert H.]

I just purchased a 1st trust deed in CA for the 1st time where the borrower had already gone MIA from the start to where his phone number was no longer in service and there was no way to contact him other than an address listed in Idaho.  Long story short I ended tracking him down at the property that was covering the loan.  The loan application said it was being used as a rental property.  I know, shame on me for not doing my due diligence so I am learning the hard way on this one, but am hoping to get some advice here.

He was about two weeks late on his first payment when I talked to him and he said he didn't have the funds at the time but would send it in the next couple days as he was waiting on a check.  I did get a phone number from him that is still working though.

I have sent a certified letter requesting payment, is there anything else I should do at this point if he doesn't pay up other than wait?  And is there going to be any added complications since he is living at the property?