teensy 3.2 dead pin??

[muggins]

I have been working on a project that involves various button inputs and an LED indicator.
All good until a few hours ago.
The pin next to a flashing LED, although set up as input pullup is generating "rogue" switches.
When I meter it the voltage is cycling from 1.1V to 3.3V in sympathy with the flashing LED on the next pin.
This happens with the Teensy disconnected from everything. I wonder has the LED output pin become compromised. I'm driving the LED to ground via 68 ohm resistor. A simple sketch to illustrate.

#include <elapsedMillis.h>
const int ledPin = 3;
int ledState = HIGH; 
elapsedMillis LedTime;
 
void setup() { 
pinMode(ledPin, OUTPUT); 
pinMode(2, INPUT_PULLUP);
}
void loop() {  
 if(LedTime >= 1000) {   
    LedTime=0;      
    if (ledState == LOW)
      ledState = HIGH;
    else
      ledState = LOW;  
    digitalWrite(ledPin, ledState);
  }    
}

 

[GremlinWrangler]

It's not impossible for ESD to do things like this, but my first guess would be that there is some stray solder. What do you get with power off if you meter between the pins? I get 19M ohm going between 13 and 14

 

[muggins]

Hi
It's not solder. The voltage on pin 2 is only drops to 1.1, unlike its neighbouring LED pin which drops to zero. I've moved the LED up to pin 4 and all is good. Must be a fault on pin 3. Should I use a FET or transistor to drive the LED?

 

[GremlinWrangler]

Pin is rated to 10mA from memory so it can drive a small LED but if you are putting anything serious on there you'll need to use a transistor/FET drive setup. What current draw did you have on your original LED?