I am working in a technology Laboratory. We have 15 BBB, an suddenly, 5 of them didn't power on any more.
They stay with the power on Led on, but nothing more happens.
Picture:
What can i solve the problem?
Thank you
Prior to solve the problem, you probably have to investigate it first.
I would verify those beaglebones are still functional:
That is, checking if the beaglebone black is displaying any messages on the serial console, The procedure for connecting a USB-to-TTL adapter is described here. I would strongly suggest to buy the exact adapter featured in the article above on e-bay if you don't have one.
If there were no messages displayed on the serial console, I would attempt to load u-boot from the serial port.
This can be done by connecting both P8.44/SYS_BOOT3/LCD_DATA3/GPIO2_9 and P8.43/SYS_BOOT2/LCD_DATA2/GPIO2_8 to the ground (two of P9.43/P9.44/P9.45/P9.46) using two 4.7 k ohm resistors, powering the beaglebone with an external 5V power supply (not by USB), and power-cycling the beaglebone - power-cycling IS required, performing a 'reset' is not enough for the new SYSBOOT configuration to be taken into account.
You can then download u-boot from your PC using Teraterm: u-boot-spl-.bin should be downloaded using x-modem, and u-boot.bin using y-modem, as described in the 'Boot over UART' section of this TI wiki article.
Once you have u-boot running, you should be able to reinstall your beaglebone using information available on the Internet.
If you cannot boot using the boot ROM and the serial port, this would probably be a bad sign.
I would suggest to try the procedure for loading u-boot from the serial port with a beaglebone you know is working, this is totally non-intrusive providing that you don't modify the eMMC from u-boot.