Well I haven't posted a fix in a while so here you go. I know this probably won't turn out as an epic thread since most people don't bother fixing the free calculators that they get at trade shows... but I guess I am weird like that.
The problem was that this little calculator was not working right. It would turn on but when you pressed the '9' key it would go off. I thought maybe it was the battery since it is several years old now. But when I got it apart the battery voltage tested good. So there is not much more to do for this guy since it is basically all chip on board (COB). But there was one .1uf capacitor sitting there so I thought what the heck, I'll unsolder it. I did and the calculator now wouldn't turn on. I tested the cap on my meter and the value was fluctuating, it never stabilized. So maybe I have found the problem. I dug up a new .1uf cap and it metered out a stable value. I soldered it in and now my little calculator is fixed! It can do five nines of uptime without so much as a whimper. Even though I lifted the traces for the capacitor in the process, a little hot glue secured everything nicely.
So there you have it, another item saved. And even though I have been trained that non 'lytics don't usually fail, I am going to guess that the ones that they put in free giveaway calculators are about the absolute cheapest ones available and thus likely to go bad.
The problem was that this little calculator was not working right. It would turn on but when you pressed the '9' key it would go off. I thought maybe it was the battery since it is several years old now. But when I got it apart the battery voltage tested good. So there is not much more to do for this guy since it is basically all chip on board (COB). But there was one .1uf capacitor sitting there so I thought what the heck, I'll unsolder it. I did and the calculator now wouldn't turn on. I tested the cap on my meter and the value was fluctuating, it never stabilized. So maybe I have found the problem. I dug up a new .1uf cap and it metered out a stable value. I soldered it in and now my little calculator is fixed! It can do five nines of uptime without so much as a whimper. Even though I lifted the traces for the capacitor in the process, a little hot glue secured everything nicely.
So there you have it, another item saved. And even though I have been trained that non 'lytics don't usually fail, I am going to guess that the ones that they put in free giveaway calculators are about the absolute cheapest ones available and thus likely to go bad.
Attached Files
.
Comment