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

Found the CRT circuitry was fried so we replaced it with an LCD unit, then found the spindle and axes work nice but a whirlygig turret showed another problem. If someone here knows a way to solve this obsolete part problem, let me know? I have work for this machine if I can get it going. converting to gang tool was mentioned but with only 4-1/2" of X travel that seems awfully limiting. I think it's a 1990, it's a Hardinge CHNC II.

Repair tech said they are reed switches? 

Repair tech said they are reed switches? 

unlikely as those would have bounce. Pretty sure those are hall sensors. I guess your options also depend on the situation like how much space do you have and whether you have a shaft to maybe couple another encoder model to. 

Is this the same or similar situation?
forum.linuxcnc.org/30-cnc-machines/1276-...hnc-1-lathe?start=18

[edit]

looks like it might actually be the very same tantalum cap that shorted.

Loren wrote:

Repair tech said they are reed switches? 

[assuming someone who'd been inside one of these things doesn't come along...here's my thoughts]

Either way, there's a magnet in the turret plate (sub-plate that engages the Hirth coupling) that triggers one of the switches when the plate is rotated to the correct position.  And likely one wire/conductor per switch, plus a power or ground wire.   My guess is that there's no 'encoding' function - just a simple one-to-one position per switch scheme.

Check your cable and see if there are 9 or 10 conductors.  If they're reeds you may even be able to do some continuity checks with a magnet (don't need power for reeds) and see which one(s) are dead.

If you don't want to try to dig out the dead switch(s), it looks like a circuit board potted in epoxy or similar.  Should be do-able to buy a PCB perf board & some hall switches (or reeds) and mount them at the same radius as the original part.  Wire/solder them to a header and connect a cable back to your control - can test the arrangement on the bench using a magnet and a power supply.

If it works, a 3d printed box or mount can be modeled/printed based on the potted board, and the whole thing coated with epoxy for oil/coolant resistance (3D printed parts aren't watertight).

There is a  shaft that sticks up just past this to mount the magnet on. There's a bit over 1/2" room under the cover.

Magnet mounts on the shaft through this, and above it.

I think @Aciera nailed it.  Looks like the cap died and blew off the potting.

Maybe you can just replace the cap and be back in business.

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.