Your power of attorney ended on his death. Now the check can only be negotiated by the legal representative of his estate. If an estate won't be opened, your mother could ask the issuer of the check whether it can be reissued to her.
BankingQuestions.com is a free service made possible by the generous support of our advertisers. Advertisers are not responsible for site content. Please help us keep BankingQuestions.com FREE by supporting our advertisers. When you see an ad for a product or service you may have an interest in, click through to learn more.