Did your dad have a chop (to cheung), if so, get the money, draw balance to zero.
If he signs name, then ask the bank if you sign an indemnity, can the bank pay your the balance. As it is not much, the bank usu pays , but to the wife/spouse, not the kid.
For such a small sum, the bank will not bother to ask you find a lawyer to do the probate as the legal fee is at least several thousands if not tens of thousands.