Hi all to summarize what I did (that might help others in the future): 1) Connector P1 pins 21 and 22 have two wires, orange on 21 and red on 22. These connect to the index phototransistor. You can connect a 10k resistor from 5V to the red wire and ground the orange wire, then connect an oscilloscope probe to the red wire and measure the time interval between pulses with a floppy inserted and the drive spinning, then "tune" the motor spindle trimmer for 200 ms pulse interval (+/- 1ms is ok, however the control circuit of the JU-570 spindle motor is very good and you can easily trim to 200.00 ms if your test equipment allow this measurement precision). 2) use the 8296D DIAGNOSTIC program that can display the rotation period error. I've tried and it works on my PET3032 too (of course only the drive speed test part). HTH Frank IZ8DWF On Wed, Feb 12, 2025 at 2:03 PM Francesco Messineo <francesco.messineo_at_gmail.com> wrote: > > Hi all, > I've just recapped a Panasonic JU-570-2 with horribly leaking > capacitors that ate a few traces on the spindle PCB. Now before > assembling back the SDF-1001 I wanted to test and correct the spindle > speed if needed. However the drive motor doesn't have the strobo > patterns, so an alternate method must be used. Does anyone know if any > of the programs on the test/demo disks can help? Images as many of you > know are here: > https://www.zimmers.net/anonftp/pub/cbm/demodisks/drives/index.html > Does anyone know any test point on the spindle PCB? I think pin 6 of > the motor controller IC could be a good place to look, but I figured > out someone must already know how to do this task. > Thanks in advance. > Frank IZ8DWFReceived on 2025-02-14 12:00:02
Archive generated by hypermail 2.4.0.