Is my stm32mp157c-dk2 board bricked?

[darla14]

Hello,

I don't know what happened but suddenly on putting the board in boot mode( boot switches ON) , I cant detect the board on the stm32cube programmer and I see a green led ( PWR_IN) continuously blinking!

attached is the image.

Please assist.

Br,

D

[PatrickF]

Hi,

LD2 is 5V presence, so, if blinking, it is likely the current limitation inside your USB Type-C supply (I assume blinking rate is very slow).

Did you try another USB Type-C supply/cable ?

Regards.

[darla14]

@PatrickF​ Thanks for the reply, Yes I did try another C type USB as well as the USB PD adapter. But same response.

Is there any IC that I have blown up and which could be causing this?

Please advice.

I have access to lab where I have soldering accessories.

Br,

D

[Tesla DeLorean]

>>Is there any IC that I have blown up and which could be causing this?

Could be any of a number of parts.

Could you have causes an ESD event when you fiddled with the switches?

Placed the board on a conductive surface?

Pull a schematic and start double checking supply rails, etc.

What if you remove the SD card?

[PatrickF]

Hi,

@Community member​ already give you a good answer.

I noted that you stated 'I cant detect the board on the stm32cube programmer'. Is it by using USB DFU on CN7 or ST-Link on CN11 ?

What is the green led blinking rate and ratio (i.e. time ON and time OFF) ?

According to board schematics, here is some investigation clues:

• Remove all connections to external (if any), including SD-Card and display flex
• If green LED is toggling, this mean there is no strong shortcut on the input. Check if there is some component heating.
• If you have access to a lab 5V supply with programmable current limitation, use it to supply the board (e.g. thru 5V Arduino or GPIO connector , without connection on CN6) with a current limitation set to a low value (e.g. start at 100mA, then increase to 500mA max). check again for heat somewhere (thermal camera is extremely helpful, but a finger might be enough).
• Could you measure the 5V voltage curve on R47 or R41 with an oscilloscope ?
• Try removing U16
• Is connecting a PC to the ST-Link CN11 (without ant other supply on the board) make LD4 ON ?

Development boards have no enclosure, so they are extremely sensible to shortcuts with e.g. metal touching components. ESD could be an issue, but there is usually enough protection.

Anyway, STM32MP157x-DK2 boards seems robust, in ST we use plenty of them without cautious and I did not ear about such bricking.

Regards