Printhead Fuse - 750A, 125V, Quick Blow Fuse
This fuse is on the mainboard of many Mutoh printers (628,1204.1304.1604.1324.1624,1638)
This is the fuse that protects the heads from power surges and shorts.
Always buy two, they blow for a reason, just changing the fuse may not fix the problem.
If you blow a fuse, you should replace the head cables, as they often are the reason for the fuse failing.