Apple IIe DuoDisk Troubles

[euta226]

Hello,

 

I'm having an odd issue related to an Apple IIe computer and multiple DuoDisk drives and controllers.  Here are my symptoms:

 

1. Using Controller #1 and DD #1, I can boot from drive A (D1), but get an I/O Error if I try to access drive B (D2).

2. Using Controller #1 and DD#1, I can connect D2 to D1's connection points on the internal PCB, and can boot from what was drive B just fine (rules out the drive)

 

3. I swapped the controller card for another that is known to be good and I repeat steps 1 & 2 above with exact same results. (rules out controller card?)

 

4. I swapped DD#1 with DD#2 using controller #2.  I repeated steps 1 & 2 above and get exact same results.

5. I swapped Controller #2 with #1 and repeated steps above with both DD drives and get the same results.

 

At this point, I get the same results, regardless of the hardware I'm using.  So, I probed my cable.  I get great continuity on all pins based on the pinout found online (rules out cable?).

 

I'm BRAND NEW to Apples, as this is my first Apple computer and have only had it for a few weeks.  At this point, I have no idea how to try to troubleshoot the issue with using any floppy drive as D2 on any hardware.  Suggestions are VERY welcomed!

 

Further details:

  DuoDisk part numbers are both A9M0108 (though the PCBs inside the DD are different)

  Both DD serial numbers are above 500000

  One DD PCB has part # 676-0107 and the other has 676-_102 (the '_' indicates a white screen print area where someone should have written an appropriate value)

  Both IO Controllers are 655-0101 and show no damage

  None of the DD internal wires show damage.

 

I appreciate any guidance you can provide!

 

James