shortcut on STM32F746G-DISCO board

[iw2lsi]

Hi all,

for those who are trying to use an external power supply on the STM32F746G-DISCO, yesterday we found that on the two cards we are using for our development, the solder on JP2 connector creates a shortcut... preventing the card to be used that way.

Best Regards,

Giampaolo Bellini

Microdigit-Elettronica.it

[Tesla DeLorean]

A solder short or cats whisker between the two pins? The photography isn't super illustrative.

Presuming a Before/After shot, but not seeing the short on the Before.

[Tesla DeLorean]

I've had these come off due to poor / cold soldering. I suspect these are attached at a different stage.

[iw2lsi]

Hello Clive,

the shorts were in both devices caused by the solder... and the pictures were taken before desoldering the jumper... after cleaning up and removing the extra lead, we were able to power the devices via JP2 + 5VExt jumper.

As you can see, there is really a little gap between the pad and the ground frame.

Best Regards,

Giampaolo

[Thierry GUILHOT · Accepted solution]

Hi Guys,

I confirm that some products (STM32F746G-DISCO, STM32F756G-DISCO and STM32F7508-DISCO) are impacted by a soldering issue on JP2. A short circuit is created between +5V and GND signals preventing the use of the board with an external power supply applied on Arduino VIN or on JP2.

The JP2 soldering must be reworked in order to remove the short circuit.

Note that a corrective action at ST board subcontractor has been deployed but as some products are in stock at distributors, you may receive faulty products for a while.

Best Regards,

Thierry,

[VUrsu]

What happens if we have faulty STM ?

At last purchase I had 4 out of 5 defects, short circuit on the 5v external port.