Casio fx4000p repair question

[Dan C]

(12-29-2022 08:20 AM)Tugdual Wrote:  Thanks Dan, yes I had seen these pictures and this is where I found I was missing that part. See the carbon film with 3 strips and a white dot? The the white dot is missing on mine and I wonder what it is made of. It seems to ensure that the main board is pressed against the carbon contact.

The whole switch is a weird choice it is simply a carbon film pressing the board and shorting two points on the main board in one position. I guess this is introducing a lot of resistance in the main power circuiit.

I can open my fx-4000p and take a real closeup picture on that white dot thing, and then maybe we can figure out what it is, and what it can be replaced with.