Hi,
I can't guarantee this method will help you
I have had sonywalkmans brick theme selves when I made the mistake of charging them in untrusted usb sockets/chargers
I have one that I haven't managed to resurect yet
Another I was sure was bricked, I purchased another one second hand, the newer one, I plugged the recharge cable that came with it into one of the dead walkmans and it came back to life, though it may have been time specific
it was one of the walkmans with the wmport cable
I have afeeling an efuse spontaneously blew itself in the wmport cable
so my suggestion is to aquire another wmport cable ans see if it helps, preferably with a safe charger,
what a safe charger is, is harder to tell these days