mitutoyo 6" caliper with bad curcuit board (2023 Update)

Ii have a mitutoyo electronic caliper that is now obsolete and the curcuit board seems to be shorted out. Anyone have experience with how to trouble s hoot this problem. It used to power up but only read in metric now it just stopped working all together.. the rest of the caliper is perfect condition . Cant just discard it?

Reply to
grbrown6
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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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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.

Reply to
jurb6006

See if you can get it apart and give it a clean.

If it has rubber carbon button and remove & clean up under the buttons. If the carbon has worn off some conductive paint might fix it.

I found on one pair of calipers the air was not able to get back under the button after it was pressed causing it to stick down. A clean up and a slot cut in the rubber fixed it.

Reply to
nub12

I'm guessing you've tried replacing the battery.

one like this?

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Several hundered dollars. for that price I'd expect a lifetime guarantee, contact the vendor, or the maker.

OTOH, I paid $12 for a no-brand 0.01mm precisionstainless steel electronic caliper on aliexpress, and $5 for a carbon fibre plastic

0.1mm precision electronic caliper.
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Reply to
Jasen Betts

All very well until they drift out of calibration and you have to throw away a work-in-progress-piece with a couple of thousand dollars worth of machining having gone into it. I'll stick with my flawless and totally reliable Mitutoyo dial calipers, thanks very much!

Reply to
Cursitor Doom

Using the conductive paint on the carbon buttons sounds like a great idea. I will try it. Thank you

Reply to
grbrown6

Thank you for taking the time with some very good tips on what choices can be made.

Reply to
grbrown6

I even tried removing a coroded resistor from the board just to lean the board surface underneath it as it looked suspicious but that didnt work, same problem aftr it wss resoldered.

Reply to
grbrown6

Mitutoyo calipers are worth fixing. I don't know what's wrong, but from your description, it kinda sounds like low battery voltage. This is a common problem that I've seen on my cheap throw-away calipers. The alkaline batteries (LR44) drop in voltage to the point where the electronics doesn't work. This is because the calipers never really turn off, draw current even when the display is off, and quickly discharge the alkaline batteries. The silver oxide batteries (SR44 and 357) are much better. The batteries still discharge when off, but the much "flatter" discharge curve of the silver oxide battery means that it will last longer. However, it to will eventually discharge. On my calipers, alkaline lasts about 3-6 months and silver oxide about

9 to 12 months.
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Jeff Liebermann     jeffl@cruzio.com 
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Reply to
Jeff Liebermann

Exactly. I remove the battery between uses... often months between uses.

...Jim Thompson

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| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
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Reply to
Jim Thompson

I bought one of the inexpensive ($20 or so) Harbor Freight models. It would kill an alkaline in about 3 months, and a silver-oxide in 6-9 months. I used it infrequently enough that I found myself expecting it to be "dead" when I needed it, and started taking the battery out when I put it away on the shelf.

I picked up a used Mitutoyo via an eBay auction. I don't know how long it will run on a single battery of either type - it's been more than a year and the first battery I put in is still quite fine.

Mitutoyo's engineers did a fine job of the "low standby current" design problem. The engineers behind the Harbor Freight cheapies... not so good a job.

Reply to
Dave Platt

The inexpensive ones (HF at under $10) have some annoying characteristics, but I've never seen 'drift'. If you're using them regularly, just keep putting in fresh batteries. If you let 'em sit on the shelf for a month, yank the battery first. And if you don't have a mechanical dial caliper, get one for the out-of-batteries times.

Reply to
whit3rd

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Reply to
Lasse Langwadt Christensen

Grin, my Mitutoyo dial calp's have slipped a few gears in their lifetime. (bought used, dial now zero's at bit past 180 degrees.) I like the lack of battery.

George H.

Reply to
George Herold

Thank you for your interest in this problem. The battery however is full v oltage and new. I could remove some more items from the board as they look corroded underneath?Other than that not sure what else to try. I did also c oat the carbon tipped buttons with curcuit writer ink to insure better cont act.

Reply to
grbrown6

George, your 180 degree problem happened to me, so I removed the cover lens e and carfully pulled the indicator needle off with some needle nose pliers and carefullypushed it back on in the correct position. Its sounds barbari c but it fixed it. Some dirt got between the rack and pinion gears and it w as a fast fix.

Reply to
grbrown6

+1

I just gave up on the electronic calipers and went to dial calipers, both at home and at work (metric and SAE). Electronic calipers just aren't worth the hassle.

Reply to
krw

When you take it apart, and loose a few screws and gears, here's a source for replacement Mitutoyo parts:

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Jeff Liebermann     jeffl@cruzio.com 
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Reply to
Jeff Liebermann

If they look corroded, they probably are corroded. That implies that some copper has disappeared, breaking a connection. You may need to reinforce the connection with a piece of fine wire in order to repair it.

You didn't bother to specify the exact Mitutoyo model number, so I can't offer any replacement PCB's. However, they probably have the same problem as yours. Mitutoyo uses "chip on board" type assembly. Here's one example: The two black epoxy blobs have IC's underneath, with wire bonds between the chip and the PCB. Although the chips is protected somewhat by a jelly like smear of junction coating, you can still break a wire bond by just touching the epoxy. An alternative failure mode is having water or corrosive fluids creep under the PCB to epoxy interface by capillary action, and eat the wire bonds. My guess(tm) is that one of these may have been what happened to yours.

Display repair: 5:32

Mitutoyo vs cheap junk Chinese calipers comparison: 16:03

Mitutoyo counterfeit: 10:15 See 3:10 for battery current measurments. The counterfeit draws 4 times the current as the real Mitutoyo. See 8:17 for video of the PCB.

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Jeff Liebermann     jeffl@cruzio.com 
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Reply to
Jeff Liebermann

More: See 10:26 for some really bad machining on a cheap digital caliper. See links under "Show More" for some more problems (temperature stability and battery consumption).

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Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
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Reply to
Jeff Liebermann

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