Hello, 3V3 power for the controlCARD is derived from the 5V0 rail of the docking station. It looks like the docking station is OFF in the "non-working board" image. 

When you say the board is not detected, do you mean it doesn't show up in Windows device manager? You can find some troubleshooting steps here:

https://software-dl.ti.com/ccs/esd/documents/ccsv7_debugging_jtag_connectivity_issues.html

Hi Gus Martinez,

Thank you for the quick reply. We would like to inform you that we are providing 5V power to the board in the similar way which we are following for the working board and it is given using docking station.

When we are plugging the board it is displayed as XDS100 Class USB Serial Port (COM 8) in the device manager. When we are trying to program the board, it is giving JTAG connectivity error as shown in the screenshot below.

By checking the schematic diagram of the TMDSCNCD28388D evaluation kit, we found out that LED D5 related to 3.3V is not glowing up which indicates that 3.3V is not up. We confirmed the same by checking the voltage at R87 resistor using multi meter and it is coming as 0.9V which indicates there may be some hardware related issue. Kindly provide support for further trouble shooting and resolving this issue.

Here are some screenshots which will help you in understanding the problem in a better way.

Thanks.

Thank for your providing the additional details. Can you try probing R85 to confirm that 5V is present on the board? If so, then all indications are that the board is defective. 

Hi Gus Martinez,

We forgot to mention you in the previous reply, we did check it. The voltage is present at the Input of the regulator.

We have checked  at R82 which is Zero Ohms and also at R85 as you said, but the problem still exists. We are suspecting there may be a hardware issue in some part of the board. Kindly let us know if there is anything else apart from these basic checks which can be tried at our end before declaring the board as defective and raising a ticket for replacement of the board?

Thanks.

Ok, will do that.

Thanks.