Кошелек стал показывать 0 баланс

GOOD DAY !

at the next start of the wallet, it began to show 0 balance. I have money for my wallet number. After the synchronization is over, the problem has not disappeared. deleted all files leaving only the backup copies of the keys themselves. Half a day was synchronization, but the result remained the same. shows that there is no money on the account. what can be done in this case