The VDDM of the nRF54L15DK is only 1.74V, and the computer cannot recognize the J-Link.

RE: The VDDM of the nRF54L15DK is only 1.74V, and the computer cannot recognize the J-Link.

Leo Mo — Tue, 29 Jul 2025 08:23:14 GMT

Yes, so I try to find out the broken components and replace them.

RE: The VDDM of the nRF54L15DK is only 1.74V, and the computer cannot recognize the J-Link.

PaKa — Tue, 29 Jul 2025 08:01:33 GMT

Applying voltage on random pins on the board is a sure way to burn it so I would not be surprised if this has been damaged if that is what you have been doing.

Default voltage on the board is 1.8V so seeing 1.74 is inside expectation. Applying 3V from the outside when the board is set up for 1.8V is not OK.

RE: The VDDM of the nRF54L15DK is only 1.74V, and the computer cannot recognize the J-Link.

Leo Mo — Tue, 29 Jul 2025 07:52:41 GMT

LD1 did not light up, but the other 54L15DK is functioning normally, so the computer is working fine.

When I connect VDDIO to 3V, LD1 will flash a few times and then go out, sometimes it will continue to flash, and the computer can recognize the J-Link.

RE: The VDDM of the nRF54L15DK is only 1.74V, and the computer cannot recognize the J-Link.

PaKa — Tue, 29 Jul 2025 07:45:32 GMT

If you have connected power outside what is specified in the DK HW user guide then indeed you may have damaged the board. Before determining that I would check with multiple different USB cables on different PCs to make sure that is not the issue.

There is a LED close to the debugger, LD1, what is this doing when you plug in the DK?

If it blinks rapidly then you have a problem with the USB cable or the connection to the PC. If it blinks and then goes stable on then they USB is working and then it could be an issue with the drivers on the PC. If it doesn't light up at all then you are more likely to have fried the kit.

RE: The VDDM of the nRF54L15DK is only 1.74V, and the computer cannot recognize the J-Link.

Leo Mo — Tue, 29 Jul 2025 07:37:50 GMT

PaKa

Hi PaKa,

The red, green, and blue wires are used to measure the SPI signal.

It should be that I connected the wrong power supply, which caused the components to be damaged?

Now the computer has difficulty recognizing the J-Link.

RE: The VDDM of the nRF54L15DK is only 1.74V, and the computer cannot recognize the J-Link.

PaKa — Tue, 29 Jul 2025 07:28:20 GMT

Can you deliver a picture of your board with the cables connected? Have you made any alterations to the board? Removed any jumpers? Cut/closed any solder bridges?

RE: The VDDM of the nRF54L15DK is only 1.74V, and the computer cannot recognize the J-Link.

Leo Mo — Tue, 29 Jul 2025 05:32:30 GMT

New content.

RE: The VDDM of the nRF54L15DK is only 1.74V, and the computer cannot recognize the J-Link.

Leo Mo — Tue, 29 Jul 2025 01:31:48 GMT

The computer can not connect to J-Link, so it can not change voltage by Board Configurator.

If I connect VDDIO to 3V, the computer has a chance to recognize the J-link, but most of the time it still cannot be recognized. It feels like the J-Link cannot start properly.

RE: The VDDM of the nRF54L15DK is only 1.74V, and the computer cannot recognize the J-Link.

rsramki — Mon, 28 Jul 2025 12:44:17 GMT

Hi Leo Mo,

Change the voltage to 3.3V using NRF Desktop -> Board Configurator.-> Select the Device. My I2C devices, while checking, were 1.8V, and VDDIO was set by default to 1.8V. Post changes, I got 3.3V. Post selection, write config and check.

I have checked in my DK and getting 3.3V in VDDM pin also.

Board configuration