Advance L24 calculator

Advance L24 calculator

NOS watches that don’t work are a pain.

And 99 times out of 100 it’s because of the battery that was installed at the factory and never taken out. Ever.

Battery acid and circuit boards aren’t a very good combination. And if you haven’t seen the damage a battery can do to a PCB you should check out some videos on pinball machine repair where the batteries installed in every solid state pinball from 1978 to sometime in the 1990s leak and the acid progressively makes its way along every track it can, corroding it in the process. Here’s a good example – in fact if you’re into pinballs and arcade games you should subscribe to this guy’s channel, he’s done some pretty amazing restoration and repair work.

And the same thing happens to vintage watches, just on a smaller scale. The worst part is seeing a watch in pristine condition on the outside, be a seething mess of blue crud and corroded traces on the inside.

Such was the case with this watch – one I hadn’t seen before – that I picked up locally for a good price. Very NOS (complete with box and manual) and very nice, I totally expected it to work with a bit of a clean with isopropyl and a new battery. Unfortunately it wasn’t to be.

It ended up needing way more than that and TBH I’m not sure how it’s actually working since it theoretically shouldn’t be.

Long story short, after trying all the conventional methods of getting it going again, I eventually brought it back to life by pretty much reversing the way the circuit works. Where there was insulation, I removed it and put something conductive instead. Not that I’m complaining – it’s a cool watch!

It has a perpetual calendar from 1901 to 2099 and you can scroll through any month during this period to find out the days and dates. The calendars jump around depending on the month, so this would look kind of cool if you could display all the LCD segments at once. The Sunday column blinks so you can tell at a glance what the day is on a particular date.

Another unique function is being able to set the date view as either EU or US (so 31 January 2015 can either show up as 15 1 31 or 15 31 1 depending on your preference). It’s got a stopwatch and alarm, 12/24 hour time and a calculator of course (no light though?) and is pretty impressive since there are no side buttons and everything is controlled via the 16 buttons on the face of the watch.

Setting it is not quite as straightforward as it is with most calculator watches, so I’ll scan the manual one of these days and upload it too.

If you find one of these, buy it – they’re usually not too expensive; but get one that works…fixing it was way too confusing!

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12 Responses to Advance L24 calculator

    • Hi – to set the Advance L24, do the following:

      1. Hold down C for about 3 seconds (00 00 flashing) press C again.
      2. Select 12 or 24 hour time by pressing +=
      3. Select US or EU date display by pressing +=
      4. Press ÷ and += to reset seconds
      5. Press ÷ and hours flash; += to set
      6. Press ÷ and minutes flash; += to set
      7. Press ÷ and year appears; += to set
      8. Press ÷ and month appears; += to set
      9. Press ÷ and date appears; += to set

      Day of the week is set automatically. Press C to finish.

      • Hi, thanks god you published your short instruction, because if you did not, I am not sure if I could have ever managed to set date and time. I just bought one from ebay exactly because I used to have one long time ago in the 80s. Nostalgia! Do you know what does the letter “A” stand for, right next to the seconds? Can you please write down a short onstruction about the alarm?

  1. I used one of these extensively in the mid-’80s. The perpetual calendar was a popular feature. My work associates would ask to use the calendar to look far ahead in planning vacations and business trips. I know that I had the battery replaced at least twice while my L24 was in its heyday. The watch was kept in an envelope after the battery ran down for the last time and then I started using a Casio Data Bank type or the forerunner of that type. I did, as recently as five years ago, know the location of the L24 in my possessions and reading your account here spurred my memory and brought on some nostalgia for this vintage timepiece. I only hope that the battery didn’t leak.

  2. I have a working one of these L24, with original box, instructions, and warranty paper. It is in very good condition. What would it be worth and how should I sell it?

    • Hi John, check eBay completed/sold listings for a good idea of current price. They vary a lot depending on condition, and yours will do a bit better because it comes with its original paperwork. Good luck with the sale!

  3. Hey John, I just picked one of these up but no manual and no old battery. What size battery does this watch use?

  4. To ‘liquid’,

    Thank you for the sequence to set this watch up correctly. I’m back in business with the Advance L24 Watch w/Perpetual Calendar. I sincerely appreciate this information. Best wishes.

  5. I was alerted to an Advance L24 being available on eBay just under a week ago. It is not the gold-toned model that I’d been familiar with for all of these decades. It’s got a light grey face, black plastic body, stainless steel back cover and a black rubber band. There’s no mistaking it for anything but an L24. The script on the face is identical to the gold-tone watch face.

    It turned out that I didn’t have the CR1620 3V battery in stock as I’d believed; those were CR2016s instead. I got into taking the back off to check to see if the battery had leaked. The watch is a brand new, old stock survivor in a blisterpack with (thank goodness) the slide-out cardboard backing. How this watch survived all this time is beyond me. The original battery hadn’t leaked. Good.

    The screws are much, much smaller than I remembered. The screw holding down the one end of the battery strap is miniscule. Once the new batteries arrived today I had genuine difficulty getting everything lined up to finally get that tiny strap screw back where it belonged. I placed the back cover on and holding everything together I looked at the watch face. After decades of laying dormant, this Advance L24 is working once again. I set up the L24 to the correct date and time and the perpetual calendar is right on the money.

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