Hello,

I'm unsure, I already sent one J-Link back as the 5V Supply seems dead, it does not supply 5V.

I try to power an STM32F4 Discovery with it and double-double-checked the wiring already.

I expected that there would be 5V available when I plug in the J-Link (measured between pin 4 and pin 19).

I don't think the wiring is incorrect as when I externally power the Discovery board I can read a valid VTref on pin 1:

SEGGER J-Link Commander V6.10c (Compiled Sep 28 2016 18:30:32)
DLL version V6.10c, compiled Sep 28 2016 18:30:23

Connecting to J-Link via USB...O.K.
Firmware: J-Link V9 compiled Sep 1 2016 18:29:50
Hardware version: V9.40
S/N: 269402916
License(s): FlashBP, GDB
OEM: SEGGER-EDU
VTref = 2.958V


Type "connect" to establish a target connection, '?' for help

On the other hand, I can't connect to the device, I still need to clarify this.

I use J-Link on Linux, not sure if this may be related to the issue.


Can anybody explain if my understanding is incorrect?


Thanks for any hints,
Torsten