TM4C123GH6PM Launchpad - blue onboard led always on. Why?

Hello Parasca,

The Transistor driving the device may be the issue. Can you replace the same?

Regards
Amit

Thanks for the reply. Do you mean the transistor that is driving the led(Q2 based on  board diagram) or other?

Best regards..

Hello Parasca,

Yes, the transistor driving the led. The device is not fried as you mentioned you have downloaded different programs. It could still be that the IO driving the Transistor may have got damaged.

Regards
Amit

I think more likely the I/O pin is damaged. Can you tell if there is a posibility that if I have damaged the pin, the whole PortF could be damaged?

Hello Parasca,

Each IO Pin is independent. A port is a logical grouping. Having said that depending on which pins are adjacent to it on the die-package, there may be damage (assuming it is an IO damage) and this may be reflected on some other port-pin.

Regards
Amit

Ok, thank you so much for information. Have a nice day!

Hello Parasca

Good news (sort of). My Launchpad is exhibiting the same behavior. Now I can perhaps see to what the issue is. In my board the code runs properly by COM port application does not work...

Regards
Amit

Amit Ashara said:

My Launchpad is exhibiting the same behavior.

Do not doctors - upon seeing patients - often develop very similar symptoms?

Blue Leds (expecially early in their development) proved extremely susceptible to ESD.  I wonder if the pcb traces (to the blue led) route to where they can be contacted thru (usual) board handling?

Beyond ESD - some blue Leds have greater sensitivity to reverse voltages.   Possibly the "undermanaged" power down of that Led may cause that (brief) polarity reversal.   Both this and (above) are mere "swags" - I know nothing of the sourcing/spec of that blue led.

I can recall several posters reporting blue Led issues - but not enough to characterize this as a, "recognized issue."   (yet)