The Aristo M400 is a scientific calculator with 8 digits precision and algebraic logic. It has 7 functions, 24 keys, and one of the early LCD (liquid crystal) displays which incorporated a yellow filter. The power source is 4x1.5V cell.
Facts at a glance:
|Power Source||4x1.5V cell|
If you have an Aristo M400 that is no longer working, you can first try replacing the 4x1.5V cell batteries. If that doesn't solve the problem, then you can consider replacing the calculator with a modern equivalent. We suggest the following current model as a replacement: