Got three pro micro clones. Two are fine and the third one started behaving in usual manner: seen by Windows as COM5, will not take sketch, changes COM state, Rx, Tx led's change state, not recignized by Windows and IDE anymore.
In short I've tried all 'solution' I could find on the net, reset, copy .hex file from good one and so far no stable result.
'Tools' I have in my disposal are: AVRISP MKII programmer, Atmel Studio 7.0, W10, Linux.
Is it possible just with this kind of programmer and Atmel to draw a conclusion board is bad?
Few times I've managed to re-flash the board using programmer and Studio, all checked good but as soon as connected to Windows it goes back to 'normal bad'.
When board is left disconnected for 15 minutes or more it will change state of LEDs. Every time something is done to the board, connected to programmer, or whatever, Rx, Lx LEDs change state:
-Both Rx, Tx LEDs are off
-Tx is on
-Both Rx, Tx LEDs are on
Clones are cheap but there should be a method we can use and confirm board is bad as it can happen with other boards.
Board was connected only few times and then did not work properly again. Board was connected to a few different computers with Linux and W10. Noted (with good one) that if I connect board to Linux
and then back to W10, board is seen as COM8 but when sketch is uploaded, it changes back to 'normal' COM5.
Everything I have is tested with two good pro micro clones and one that is bad, so there is no issue with programmer, cables, test procedure, software.
I have pages and pages of recorded screens etc but the point here is what is the minimum hardware/software that we can use to confirm board is good or bad?
Or is there a 'step-by-step' basic test?