Unfortunately thing like that are like toasters. One IC, surface mount at l east, maybe even using the board as a substrate with a glop of epoxy over i t. If you can't get the board it is over.
If it has the markings to read it as a regular old time caliper you can use it like that. Or you can use it as a transfer device. Also, if it has the
30 degree cut in the depth gauge it also makes a good tool to measure the d iameter of a hole.
What almost amazes me is that these things can tell the position even with the battery out. Mine has a zero button but that is almost not necessary. I cranked it out to like 3" and took the battery out and when I put it back in it remembered where it was. Is this by memory or some sort of measuremen t technique of which I am not aware ? They talk of capacitance but there is no way that could be accurate at 6".
Mine is an elcheapo, but it does allow for measurement without the battery, and I think most do. And they are cheap so you can just buy another one. I hate to say that but when something is unfixable it is unfixable. You can either get the part or not. You can hound the company, and they might even agree to "fix" it for you but what will happen is they will replace the uni t. I work for factory service (not there) and when something cannot be fixe d we just offer a replacement at a discounted cost.
I wish we had more control over what the actual manufacturers do but we onl y bought half the company, what's more all the stuff is made by Apex, this company is just a US front. No more detail on that.
You might find a used one online with bent jaws or something and be able to use the board from that. But there is no ordering "IC 12", replacing it an d having it work again.
Nother thing to consider is what these things cost. Mitutoyo is a really go od company and I have some of their micrometers and other things, but the f act is they are selling their name if you cannot get parts. So for, I think $16, Harbor Freight or one of them has one that is so similar in performan ce you'll never notice any difference.
Or just read a real caliper that has the scale on the side that gives you t housandths and forget about this digital shit and you will never have this problem again.
On this page the first picture shows a caliper that can read down to the th ousandths :
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reading-1/
Forget the text. The top of the picture shows a different scale which is ma de specifically to reveal the next decimal place. Whichever line lines up w ith a line on the main scale indicates the next decimal place. They achieve that by using nine lines in the exact space of ten. It does not matter whi ch line lines up with the main scale, just count it up and it is the next d ecimal place.
I know this is hard to understand for modern people, but give it a try. The battery died in my digital caliper about two years ago and I never bothere d to replace it. Plus I got better calipers laying around anyway. They just aren't digital and you have to really look at them to read them, it is not all done for you. I also have a pretty full set of micrometers, none digit al.
These conveniences are nice but make us lazy.