I am having an issue with my DSO. The trigger LED always remains on and I am unable to use any keys. But if I press the "SEL" key, "save" appears on the screen, which is a clear indication that "+" key is pressed. I have checked the key and it appears to be shorted with ground. I tried removing the tactile switch, still same issue. I am not sure if the pin is internally shorted or there is some short on board. Please help me to resolve the issue.

 

Welcome to AAC!

I tried removing the tactile switch, still same issue.

Does this mean that when you remove the switch it's still shorted? Or does it mean there's still a short on the board?

Do you have the schematic? Is this a kit that you assembled? Did it ever work?

There's not much that can go wrong with the switch.

 

Does this mean that when you remove the switch it's still shorted? Or does it mean there's still a short on the board?

There is still a short on the board. (Earlier I thought the switch could be faulty)

Do you have the schematic? Is this a kit that you assembled? Did it ever work?
There's not much that can go wrong with the switch.

The schematic is same as shared by you. There is nothing much to go wrong. I guess the uC is internally shorted. Can this happen?

 

I guess the uC is internally shorted. Can this happen?

Yes it can.