CA Com Code Section 2512

(1)

Where the contract requires payment before inspection nonconformity of the goods does not excuse the buyer from so making payment unless (a) the nonconformity appears without inspection or (b) despite tender of the required documents the circumstances would justify injunction against honor under this code (subdivision (b) of Section 5109).

(2)

Payment pursuant to subdivision (1) does not constitute an acceptance of goods or impair the buyer’s right to inspect or any of his remedies.