Need help with Atari LYNX - NO A or B Buttons

Hi All I picked up a vervy clean Atari Lynx today from the thrift store for $10..

I have pulled it apart and cleaned everything inc. the flex membrane for the buttons. All the Power and pause ect. works but I get no A or B (Either).

Is this a common fault?

 

Anyone know where I can get a new mambrane part?

 

are both sets of buttons not working or only the lower set? Good find BTW, I had a Lynx at launch, sold it a couple years later and have always wanted another. Gauntlet and Roadblasters are must-have games.

 

Both sets dont work but all the option and power ect work, cant test the d-pad.. I only have the one game , casino.. Could it be the cart, because when I turn it on The title flashes up for a second then goes black then plays the intro. But as I said both A and B buttons don't work...

 

Also the back of the game has like a scorch mark where the rom is..

I thought I'd enlighten some more on the motherboard, the board is clean no leaking caps BAR ONE, I did not see this at first but one of the 100uf ? caps going from the power mossfet leaked a little. no corrosion on the PCB but a resistor going off it to the mossfet(transistor?) reflowed the points (even though the system worked fine)..

 

If both sets of buttons are not working I'd suspect a problem with the control circuit, have you tried bridging the button contacts with a conductor with the casing open and the Lynx running?

 

No I have not but the other keys work... wouldn't that suggest the controller is working?

 

Could be completely different circuits, can you take a picture of the board showing the button contacts?

 

Does anyone have the pinout for the connector?

 

I can short it out and turn it off and on but nothing else