can give you an indication that the head is good...
beware using an
ohmeter on magnetic heads, unless you have a degausser for same and use it
afterwards - the DC voltage from the ohmeter will magnetize the head, and
this is a Very Bad Thing for subsequent tapes.
Is this still a problem with modern digital ohmmeters? It certainly was a
problem with analogue ones. I once went on a merry dance finding why a
Sony reel-to-reel VTR was giving low head output, it turned out I'd
magnetised the heads while checking them for continuity. Not enough to
damage tapes, but enough to upset their magnetic characteristics...
-tony