Unisonic 839 SQ
The Unisonic 839 SQ is an arithmetic calculator with 10 digits precision and algebraic logic. It has 7 functions, 24 keys, and an LED (light-emitting diode) display, typical of calculators of this era. The power source is 4xAA.
Facts at a glance:
If you have a Unisonic 839 SQ that is no longer working, you can first try replacing the 4xAA batteries. If that doesn't solve the problem, then you can consider replacing the calculator with a modern equivalent. We suggest the following current models as possible replacements: