Hardware issues

[electronicsLearner77]

I am basically a firmware engineer but presently i have an emergency where i need to debug the hardware issues.

1. I am seeing several micro controller failures, i reached this conclusion as i could not flash the microcontroller. I wanted to know if i probe the micro controller pins using the oscilloscope and if two adjacent pins gets shorted does it damage the micro controller?

2. If i power the hardware board with a regulated power supply of 5V it goes to CC mode, the voltage does not increase unless i increase the current. When this kind of situation arises does it mean some of the pins are shorted? How do i debug such issues?

 

[Alec_t]

Welcome to maker.pro.

if two adjacent pins gets shorted does it damage the micro controller?

1) It might well do, depending on what the pin functions are and what the maximum allowable pin currents and voltages are.
2) Depends on the board design. Voltage where? Current through what?

 

[Harald Kapp]

if two adjacent pins gets shorted does it damage the micro controller?

Possibly, depends on which pins you shorted

When this kind of situation arises does it mean some of the pins are shorted?

Not necessarily, simply means the circuit requires more current than you initially allowed for.

How do i debug such issues?

First youi need to know the expected current requirements of your circuit. Only then can you judge whether the actual current is too high or not.
In case it is too high, you need to find the culprit. Depending on your circuit there are many possibilities.
For example:
- check the current drawn by an empty (unpopulated) pcb. A short circuit between traces can be found in this way.
- check for componnets that get unusually hot. If you find some, check the correct assembly of these componnets to the pcb and also check the correctness of the pcb traces leading o these components.
- check the correct working of the firmware. Trying to push an output pin's voltage agains another driving pin may lead to a short circuit. Keeping the µC in reset while probing for current drawn may help in this case as often GPIO püins are input during reset (unless fused to be outputs).
...

 

[electronicsLearner77]

The current is more than the expected and the micro controller gets heated, how long can i micro sustain in heated condition? Can i say a hardware design is good if it works for some days or weeks and then fails, i mean when can i trust the hardware is ok to continue or improvements required.

 

[danadak]

You might be experiencing triigered parasitic scr problem in CMOS :

https://www.ti.com/lit/wp/scaa124/scaa124.pdf

Regards, Dana.

 

[Harald Kapp]

how long can i micro sustain in heated condition?

No genertal answer to that. Depends on the specific conditions.

Can i say a hardware design is good if it works for some days or weeks and then fails,

No - unless you design for planned obsolescence. Then it may be good for you, but not for the customer. And consequently in the end not good for you.

when can i trust the hardware is ok to continue or improvements required.

The minimum requirement is that all components work within their specifications. All their specifications.
Also signal quality needs to be good and last not least the circuit needs to perform as designed/expected.
Depending on the complexity of the circuit a little or a lot of testing may be required to ensure this.