I'm out of ideas. I don't know enough about the circuits and processor though, but I know a man who does... Hopefully Jeremie or DJ will have an idea.

@Rich... As good as EZ Robot is with warrantees it's just not worth the hassle of returning it... The only 2 ports affected are 14 and 15... I can live with it... However, any thoughts from Jeremie would be welcomed...

Thanks for letting me bounce this off of you guys...

Cheers Richard

OK, your trouble shooting show it's on the EZB and not the computer. I guess you started a new project on the new computer? Did you look at the traces and header pins on the EZB like I suggested? It may be as simple as a sloppy soldering job and there might be a spot of solder somewhere shorting the two signal pins together. I've seen this a few times. Heck, I've done it myself to board repairs. Sometimes you cant even see it. Just a simple brushing and cleaning with some spray Flux Cleaner can clear this up. If it's under the header pins then the only way to clear that up is to desolder the header, clean it up and resolder it. However this may be going farther then you want to go.

If a simple visual check doesn't show anything you may want to send it backfor a new one before spraying it with flux cleaner. That may void your warranty.

Hey @Richard R,

It sounds like a manufacturing defect to me, likely a solder bridge on the chip itself. There's current limiting resistors in series with each digital pin so they could be masking the short on the digital pin side, hence why it doesn't look to be a D14/D15 short circuit. This a very rare occurrence but it can happen. We could definitely warranty it.

But since you mentioned that you don't want to deal with the hassle of returning it, you could always take a magnifying glass to look at chip you might be able to see a solder bridge. Wish I was in your neck of the woods, then I could fix er' up with the swipe of a soldering iron. Do you have a hackerspace near you with some people with SMD soldering skills?

Lol, I was writing my post at the same time as @Dave. Great minds think alike.

@Richard R, great troubleshooting by the way

Thanks for the complement @Jeremie. It's good to be validated.

Thanks @Jeremie and @Dave.... Going to pop the plastics off and have a close look at it for a "solder bridge".... LOL... Jeremie, you're a young guy with better eyes (and soldering skills) than me... I'll take a crack at it..... What's the worst that can happen?... create another solder bridge on 2 other ports....

You could try carefully dragging the tip of an exacto knife between the feet of the chip or where ever you find the bridge.