Dukerc51

Well that is good news that the PLC works when it is out of reset. Post a photo showing which connector you removed, I may have made a mistake in my notes and counted wrong.

On my system the two MDI cards are not the same and are not interchangeable!

Attachment 293688

The card on the left is the 24 out / 8 in card that is the furthest from the power supply in the card rack. The one the right is the 8 out / 24 in card that is closer to the power supply in the card rack. The spindle speed control is connected to the 24 out / 8 in MDI card.

Attachment 293690

The 24 out / 8 in MDI card is the bottom one in this photo.

Attachment 293692

24 0ut / 8 In MDI card.

Attachment 293694

8 Out / 24 In MDI card.

I think there is a problem with your 24 out / 8 in MDI card. The problem(s) are not likely the same as I had.

Attachment 293696

This is a likely problem area of the card, if I didn't make a mistake in my notes, it is looking likely that I did because of the replaced IC on my card. Use a magnifying glass and carefully inspect this area for any bits of swarf or corrosion. Clean it really well with rubbing alcohol and blow dry with clean dry air. My card had corrosion (broken traces) under the tape under the LM317s (big three terminal ICs at top). On one of sheets I posted this morning is a sketch of the typical output channel schematic. If I had to guess I think that there is either some swarf stuck somewhere or that IC10 and IC12 (UDN 2982A, get them off of ebay from china) have gone bad. I had one fail on my card along with several LM317s. Parts and Smarts can fix this card easily, it shouldn't be too much, under an hour labor.

John