Looking for a replacement or way to fix my smoked turret encoder on the CHNC II

By the way, if anyone has a oem wiring diagram for this, I'd love to have a copy.

After I somehow get under the coating. That stuff is pretty tough.

tommylight wrote:

The small chips have 4 pins (if i have not gone blind), so dual output hal sensors or 2 or reed per chip?
A DVM and 2 minutes of time would answer that.

Unless you have a wiring diagram, disregard what I wrote earlier about fabricating something up quickly.  My response was a little hasty, and @Aciera posted that great link while I was still writing my response.

The thread @Aciera linked to shows some photos of the assembly without the potting compound, and yes - there are a bunch of other components under there that weren't obvious from your pic.

The big burned spot at the lower left of your board appears to be the same component (same location) that blew up on JT's (I think) board years ago.

As Tommy pointed out, those look like 4-pin hall sensors, and the other post indicated they were halls, too.  But I suspect that your sensors - reed or hall - aren't the problem.  Or aren't the only problem.

Potting compounds can be a pain, but I'd try heating it with a heat gun to see if it softens then start picking it off.  MEK and xylene can also dissolve some potting compounds.  If you can get to the burned component and replace it it may work without having to strip the whole board.

Regarding the magnet, read the other thread. It looks like there's a post with a magnet on it - not embedded in the underside of the turret plate like I first suspected.  The magnet appears not to be keyed to the shaft, so it's possible to adjust the trigger point.  The other thread had a post where the author advanced the magnet a bit to tweak the sensing time in relation to the locking mechanism teeth.

Fundamentally, you could fabricate your own sensor but you need to know what signals the controller expects to see.  5V? 0V? 24V? Sinking or sourcing?  i.e. you need a wiring diagram of some sort.

Loren wrote:

This tiny print on the phone is too hard to follow, I'll get back to you on the pc later, but there are 6 leads out of this unit.
 

And there are two IC chips in the earlier post, too.

Eight halls (or reeds), plus two IC's, plus six wires means that the assembly is an encoder of some sort - not a direct input-output configuration.

More evidence that my first post was way off base and hacking something up isn't really feasible without knowing something about the signals the controller expects to see.

Is it common to find only one component on a board burnt, fix that and you're good to go? I would have never thought that, but BigJohnT's thread leads me to believe that?

Sure, sometimes it's just a single part, although in your case you may have to replace the adjacent part as well, the value of which you might be able to read off of a photograph in the other thread.

[edit]
seems to be another, smaller capacitor