Acurite III Display Issue

I have a mill that came with an Acurite III DRO. The table scale and display seems to work fine. The saddle display seems to be missing some digits. A quick review of the manual I found on line does not seem to offer any ideas. I know it is an older unit but does anyone have any ideas before I really dig into the manual? Sorry for the sideways picture from the phone.

Thanks.

Dale

I doubt the manual will give you much to work with, unless you managed to scrounge up a copy of the tech manual, which I think Accurite was pretty tight fisted with, if they even printed one.

Here's my two bits and a non-electrician.

Most of the problems I have ever run into in electronics of that nature that did not work, were mechanical issues. Broken wires, bad solder joints, corrosion, and the like.

If you cannot see any obvious broken wires, etc., look at the numbers on the LED segments and see if they are still available. If you can, find the pin-outs and test to see if the segments themselves are working. Off the top of my head, a 1.5v battery is usually enough to get the individual lines to light. 'Course, you gotta find the ground pin too, and watch polarity. I don't recall ever frying a display segment by reverse polarity, but...

Before anything else, check that the problem does not follow the scale, by swapping the scale connectors and seeing that the scale from the bad segments does work on the good display segments.

But I would likely start by looking for corrosion or a bad connection in the front panel with the segments mounted on it.

If the segments are set up with plugs, and can be swapped internally, that is another tool to cross check whether the problem is before or after the plug.

Anyways, good luck, watch the big ol' capacitors!

Problem Solved

Trevj -

Thanks for your reply - and I got a chuckle.

I'm a retired guy who spent his working life in engineering management, mechanical engineer by training. 46 years ago I unintentionally ended up as a computer programmer for about6 years. Some of that time doing diagnostic software on aerospace computers. One thing you learned early in that was that most of the problems were related to connectors and cables. Also, sometimes it is so hard to isolate that you ended up 'flipping a coin' to make the call. And also that sometimes an indicator of some type did a wonderful identification of the problem. That 3d reason was why I posted the picture, knowing nothing about this box. Figured it was worth the shot that is was 'you idiot, loose pin 7 in connector 3' kind of issue.

Saw your reply when I came in for lunch. Went back out to the shop saying - yeah, you know that, open it up - took your prodding for me to move. The box was immaculate inside - and not bad outside. This mill came out of a high school 10 years ago and has just been sitting until I finally got it going yesterday - machine and dro both low hours. Popped the two flex tapes and four other connectors off the board and pulled it. For a piece of commercial gear it is an elegant and robust design mechanically. Design engineer must have known how to maintain things. Displays are mounted on boards that connect to the main board with typical connector to the pin soldered in thru hole. I thought about trying to pull and swap them but decided to not do that first pass. Looked the boards over - simple 2 sided pc board - traces looked pristine. Put it back together, hit the power and she came up fine. Probably just enough oxidation in one of the connectors to foul it up, even thought the pins looked fine. So we will write it up as a NPF (No Problem Found) and return it to service.

Thanks for the poke!

Dale