It's hard to say without seeing the agreement, but you may be able to sue him for breaching the agreement. I would contact a local attorney. For one thing, it's hard to know -- from your presentation alone -- whether the agreement is enforceable.
Please see Section 17-1 (B) (2) of the attached link, below. The maker of the check has an obligation to make the funds good. You have a cause of action of the party does not make the check good. I also believe that the check 1) is evidence of a contract to pay, and 2) reopens the statute of limitations. You should contact a collections attorney.
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