ORA-10567: Redo is inconsistent with data block

Oracle Database 12c Standard Edition Release 12.1.0.2.0 - 64bit Production.

Database - In No archivelog Mode.

Red Hat Enterprise Linux Server release 6.5 (Santiago)

Database was in MOUNT stage after restart. Below erros where found in alert log

Reading datafile '/database/as3phc/undotbs01.dbf' for corruption at rdba: 0x00c42d88 (file 3, block 273800)

Reread (file 3, block 273800) found same corrupt data (logically corrupt)

Mon Mar 26 12:34:24 2018

Aborting crash recovery due to error 1172

Mon Mar 26 12:34:24 2018

Errors in file /oracle/diag/rdbms/as3phc/as3phc/trace/as3phc_ora_3766.trc:

ORA-01172: recovery of thread 1 stuck at block 273800 of file 3

ORA-01151: use media recovery to recover block, restore backup if needed

Mon Mar 26 12:34:24 2018

Errors in file /oracle/diag/rdbms/as3phc/as3phc/trace/as3phc_ora_3766.trc:

ORA-01172: recovery of thread 1 stuck at block 273800 of file 3

ORA-01151: use media recovery to recover block, restore backup if needed

ORA-1172 signalled during: ALTER DATABASE OPEN...

...

...

Reading datafile '/database/as3phc/undotbs01.dbf' for corruption at rdba: 0x00c42d88 (file 3, block 273800)

Reread (file 3, block 273800) found same corrupt data (logically corrupt)

ERROR: ORA-00756 detected lost write of a data block

Slave exiting with ORA-756 exception

Mon Mar 26 14:17:44 2018

Errors in file /oracle/diag/rdbms/as3phc/as3phc/trace/as3phc_pr04_7333.trc:

ORA-00756: recovery detected a lost write of a data block

ORA-10567: Redo is inconsistent with data block (file# 3, block# 273800, file offset is 2242969600 bytes)

ORA-10564: tablespace UNDOTBS1

ORA-01110: data file 3: '/database/as3phc/undotbs01.dbf'

ORA-10560: block type 'KTU UNDO BLOCK'

Solution:-
Tried :-

SQL> recover database;

SQL> recover database until cancel;

SQL> recover datafile 3;

Got almost the same errors :

Reading datafile '/database/as3phc/undotbs01.dbf' for corruption at rdba: 0x00c42d88 (file 3, block 273800)

Reread (file 3, block 273800) found same corrupt data (logically corrupt)

ERROR: ORA-00756 detected lost write of a data block

Mon Mar 26 14:24:50 2018

Media Recovery failed with error 756

Finally, did :

$ rman target /

RMAN> recover database allow 1 corruption;

exit

SQL> alter database open restlogs;
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