13 Feb
2011
13 Feb
'11
2:13 a.m.
I am talking about the motor PCB end. 7 of the wires
are soldered to the
PCB in a row of 3 and a row of 4 IIRC. I couldn't see any sign of that
white wire on your photos of the top of the motor PCB, so I am wondering
what happens to it. Is it soldered to some point on the underside (solder
side) of the motor PCB, if so, where.
In this drive it seems to be a row of 3 and a row of 5 rather than 4. The
white wire is can be seen in that set of 3 of the left part of the board in
this photo.
http://www.classic-computers.org.nz/temp/2011-02-14-400k-sony-motor-circuit…
There are 3 capacitors connected in a start (`Wye')
to the motor winding
connections. Ifthey're defective, the back emf from the windings can
damage the chip.
Tony ..."connected in a start (`Wye') to the motor winding connections."
I'm not sure what you mean by this. What is a "wye"? Pardon my ignorance
in these matters.
I realise we had no circuit diagram for this particular drive, but would
those capacitors be obvious from their positions on the board? Can you see
them in the photo under the link?
BTW, you'll notice the motor board is a little dusty. It's cosmetically the
worse of the two drives. I figured if I was going to cock something up
during this disassembly diagnostic process I'd rather do it to the drive
with the most obvious ravages of time. The second drive (same fault) is
much cleaner.
Terry
Terry