CASIO fx-5000F Scientific Calculator made in 1991

With 128 stored formulas ready to be used, this model was very popular among students and professionals at the time, and it is probably one of the best pocket calculators from the 80's.

I opened it to clean the case and keyboard.

General parts view.

The Printed Circuit Assembly.

IC's:
- Hitachi HD62001A04 1G 33 processor (1991)
- OKI M5268V-H1  1716 controller
- Hitachi HD61914C 1G 43 1KByte SRAM  (1991)

The HD62001 processor is used in several Casio and OEM calculators only changing the firmware, for example:
- Casio fx-3900P: HD62001A01  6L 13
- Radio Shack EC-4023: HD62001A04 (OEM of fx-5000F)

Rubber keyboard painted keys.

Keyboard  membrane over the rubber keyboard, PCA side view.
 

 Keyboard  membrane, keyboard rubber keys side view.

PCA installed over the keyboard membrane.
Note the shielding/grounding spring at the top center.

 

Inner frame latches, at the display side.
 

Power switch in its bed at the inner frame.

Inner frame in place over the PCA.
Six self tap screws fix it in place.
Note the shielding/grounding spring at top center. Care is required to inset it in inner frame pass thru hole, while keeping the power switch in the correct position. 

2 x CR2032 batteries for a total of 6Volt are required to power this unit.

Full contrast on to show all the LCD pixels and annunciators.

This is a beautiful and feature rich calculator.
Forensic test result: 9.0000156854