Nested If shows #VALUE

I have below formula. Its working for two first conditions.

=IF(F3="","",IF(F3="RUB",IF(FIND("2600",J3),MID(J3,FIND("2600",J3),14)),IF(F3<>"RUB",IF(FIND(":59:",J3),MID(J3,FIND(":59:",J3)+5,14),IF(F3<>"RUB",IF(FIND(":59F",J3),MID(J3,FIND(":59F",J3)+6,14)))))))

but if if met below condition , it shows #VALUE!

IF(F3<>"RUB",IF(FIND(":59F",J3),MID(J3,FIND(":59F",J3)+6,14)

Is there any suggestions how to get it work?I tried to combine with OR and with IFERROR, but give no result.