Hi guys,

what a great place here! Found it incidentally thru google

Well, here my problem. I’ve a Casio 81QS-35 in a very great condition, almost NOS. The watch was running fine over the last years. Since a while ago the display disappears and I thought now its time for battery replacement.
After opening the watch I realized that it needs a CR2320. As soon as the new ordered battery arrived, I’ve inserted and connect AC and + for a few seconds. Turn around the watch and nothing happens :( After I’ve pressed the light button, the watch showed me 12:00:00 and start to count the seconds until 03 and the display disapperas again :( If I press the light button again, the same thing happens again. If I continous press “light” the watch runs perfectly wink But that couldnt be a solution. The beeper sound is pretty loud and the light well bright, so I believe the battery is not to weak. It’s a Varta CR2320, exp. date is Oct. 2023.
Does someone have a clue what could be wrong? Thanks in advance

I’m a noob at digital watch repair, but maybe you need to remove the battery for a few minutes and try again. I do know that you should not use metallic tweezers to manoeuvre things inside the watch. Maybe you need to press the AC button a little longer.

Thanks for the answer C45w, I’ve that already tried. Remove the battery and install again. Also connect AC with + for 30 seconds :(

Well in that case you could test the old battery you removed with a multimeter to see how discharged it is. If it has a good charge then the problem lies within the watch electronics.

Now, after replacing with a 2nd new ordered fresh battery the problem still exist. So, maybe the electronic is dead or tired :(