No STM32 Found on ST Link V2 JTAG Port

[sdobbie]

Before ST started bricking counterfeit st link V2 units, I was able to program my board without issue. I bought a confirmed genuine ST Link V2 from RS components and connected it exactly as shown, but it never connects to the target and all I can get is this output or an error which says no target found. I managed to upgrade the ST link firmware so it is connecting to the PC normally.

23:34:26:388 : STLinkUSBDriver.dll loaded
23:34:26:394 : STLinkUSBDriver.dll loaded
23:34:26:394 : ST-LINK SN : 37FF6C0630484B3838261443
23:34:26:394 : ST-LINK FW : V2J38S7
23:34:26:394 : Board : --
23:34:26:394 : Voltage : 1.05V
23:34:26:395 : Error: ST-LINK error (DEV_TARGET_CMD_ERR)
23:34:26:410 : Disconnected

[Uwe Bonnes]

Your setup is incomplete. E.g. VCAP capacitors are missing and so the core will not work. Try first to connect to a  known working device, than correct you schematics , the try again.

[Tesla DeLorean · Accepted solution]

VCAP both need 2u2F

You also need to connect VTarget to the 3.3V supply for the authentic ST-LINK/V2 so that the voltage reads closer to 3V rather than 1V

[sdobbie]

I forgot to mention that I have omitted all the power supply components from the schematic for the sake of simplicity. The board worked well on the fake ST link before ST started breaking them.

[sdobbie]

Your suggestion of connecting VTarget to 3.3v solved the problem. Thank you!