Oven circuit board

My wall oven microwave combo unit membrane keypad has failed. Parts for the unit stopped being made many years ago.

A new oven is above $3000 plus $500 installation.

So I decided to make a replacement keypad myself.

I decided to use push buttons in place of a membrane.

There are 22 buttons in all that are matrixed into a 10 wire dupont sized ribbon connection.

I've gathered the push buttons and a prototype circuit board plus the keypad matrix map for the existing membrane.

I'm having trouble visualizing the circuit I need to create. That is, I have a schematic to follow but I'm not sure how to translate that schematic into a real-world circuit layout.

Help me figure that part out.

Gary

PS I am including photos but they seem to be too large to post in a single entry so I'm adding them in a second entry.

keypad matrix.

Prototype board.

It isn't hard.

Think about what you have in your diagram.

All switches in row 1 need to have one terminal connected together.

All switches in row 2 ditto......connected together

and so on.

Now all switches in column 5 need to have the unterminated terminal connected together

Column 6 ditto

and so on.

Hope that makes sense.

I would suggest you get a piece of perspex/lexan to mount all your switches then you can make all your connection on the rear and you can do away with the prototype board. You then just need to connect the 10 wires to the input to the oven controller.

I see the keyboard layout but no schematic.
Do you have one ? (have you reverse engineered it ?)
Do you have the 22 x 2 connection points identified ?

windoze_killa:
Hope that makes sense.

I would suggest you get a piece of perspex/lexan to mount all your switches then you can make all your connection on the rear and you can do away with the prototype board. You then just need to connect the 10 wires to the input to the oven controller.

That DID make sense. Thanks. I was able to lay out the matrix from your description.
And you were right about using lexan rather than the prototype board. I did just that.
Gary

raschemmel:
I see the keyboard layout but no schematic.

You are correct. I was not able to locate a schematic. But the membrane keypad is simply a bunch of switches so the circuit is VERY simple.
Gary

TAP Plastics sells special super sharp pointed drill bits (PLASDrills) for drilling lexan without cracking it. They might also have plastic dowels you could use as legs.