Calculator Insides

Casio FX-502P

Click picture to enlarge

This is a picture of a disassembled FX-502P. Even on the enlarged picture it is not quite possible to make out the numbers on the 3 chips. In descending order, they are 'HD43109 9F 25', 'HD43109 9F 25' again and 'HD43108 9D 31'. There is however a noticeable difference between the top 2 chips. The middle chip has half of its legs cut off! The FX-502P was not exactly an optimized design!

Note that this is my machine which has a broken power switch. You can just make out that there are only 3 contact 'wipers' where there should be 4. You can also see the crack in the yellow screen protector. Click image to enlarge.

Click picture to enlarge

Another picture of the disassembled FX-502P. I turned over the back plate and the circuit board. Note that the LCD is attached directly and firmly to the board unlike the later fx550. The backplate advertises the minimal power consumption of 0.0008W and with the the FA-1 adaptor of 0.001W.Click image to enlarge.