# Hewlett-Packard HP 27S (Pioneer MENTOR)

The Hewlett-Packard HP 27S is a scientific calculator with 10 digits precision and algebraic logic. It has 250 functions, 37 keys, and an LCD (liquid crystal) display. The power source is 3x1.5V cell.
**Note:** Extremely powerful formula programming and solve functions.

## Facts at a glance:

Feature | Value |
---|---|

Type | Scientific |

Functions | 250 |

Keys | 37 |

Precision | 10 |

Logic | Algebraic |

Display type | LCD |

Display size | 131 |

Printer | IR ext |

Length | 148mm |

Width | 80mm |

Thickness | 15mm |

Weight | 120g |

Power Source | 3x1.5V cell |

Year introduced | 1988 |

Year discontinued | 1991 |

## Diagnostics

Note that diagnostic tests generally delete any data on the calculator. Be sure to back up any important information held in the calculator before running these tests.

Hold down ON button and press fourth key on top row of keypad, then choose test from menu (use EXIT to leave test and go back to menu). Use ON and fifth key on top row to run a test sequence. Use ON key and third key on top row to reset calculator after tests.

## Replacements:

If you have a Hewlett-Packard HP 27S that is no longer working, you can first try replacing the 3x1.5V 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: