STM32F4 Discovery cycling on/off

[Nipuni Perera]

This failure happened suddenly with no apparent cause. The board started cycling on/off at a fairly regular frequency (as shown in the attached video). When this happened, LD1, LD2, and LD7 all cycled on/off (LD7 never turns on in normal operation, and I don't use CN5).

I changed the cable, and the problem appears solved. However, I use an FTDI board to communicate. When I used the cable I used with the Discovery board with it instead, at first it worked with no problem. After a while, however, the same problem appeared, with the Discovery board turning on and off (with no apparent change in the FTDI board, which was connected to this cable). Then I used a different cable with it, and the problem appears to be gone for now.

My questions are,

1. Is this a problem with the cable?
2. Or is it a symptom of an underlying problem with the board? If so, is there any way I can fix it if the problem appears again?

Thank you very much for reading this, and I appreciate any help I can get.

[T J]

change the power supply...

[Nipuni Perera]

The power supply is via the USB cable connected to the laptop.

[Tesla DeLorean]

So perhaps continuity issues with the cable/connector. Issues with excessive loading on the regulator. Issues with the soldering and/or components on the board.

Issues with the supply on the laptop.

Try running the board from a USB charger (use current fw)

[T J]

If the board has a problem, you could use your finger to check if something is hot.

otherwise, a nice big power supply should be able to pinpoint the issue for you...

just make sure you have safety glasses on first.