Most heads have two sets of windings. One for trim
erase and a second
for read/write. The organization varies but the trim is two pins or
have one pin in common with R/W and the RW is often a centertapped
winding (three wires) so you should see three connections of near
zero ohms and a pair that are also near zero OR 4 pins that show
near zero (common wire case).
The test for alignment usually requires a calibration disk and scope
but I've done it by doing reads of a known good disk and "finding
the edges" and setting it for the middle. Track 00 is usually less
critical so if it happens when the head out and you can boot or read
the disk thats usually good enough.
Allison
Allison - thank you very much. I've measured the replacement heads and it
looks like they may be damaged. There are 5 connections to each head - on
the upper head, 3 connections measure zero, and on the bottom head, 4
connections measure zero. The bottom head is consistent with another head
(damaged) I have. I know that the replacement heads were able to read data,
but caused the tracks to erase when writing, so I still would expect to be
able to use them.
The major question I have, though, is how do you change the position of the
head to calibrate it? On the MPF-52W-30 (sorry I inadvertently gave wrong
number last time) there's a variable pot RV101 and 2 pins to IC101
(CXD1007B) associated with X-adj and X-reset. Other than setting the
position of Track 00, these look like the only options available to move the
heads a fraction of a step.
I'd be grateful for any thoughts or suggestions.
Peter