STM32F0 - Error: Data read failed

[panoss]

I have an STM32F030K6T6, I 've made a custom board.
I 'm using STM32CubeProgrammer with ST-Link V2.

I click 'connect' and I get this error: 'Error: Data read failed'

It gets connected to the MCU, the program reads correctly it's ID.

I have checked all related connections: SWCLK, SWDIO, RST, 3V3 and GND. (I 'm not using the SWIM).
Everything looks ok.

I 've tried both options of BOOT0 (grounded & pulled up to 3V3).
 
So what might be the problem? A damaged MCU? (maybe I overheated it during soldering)

 
And if it 's damaged how does it get recognized by the STM32CubeProgrammer?

[thm_w]

3.3V is supplied to the board by the stlink or is it being generated locally? Have you checked the supply is stable enough?
Look at the pins under a microscope if you can.
Check signals with an oscilloscope during probing.

Very unlikely it was overheated during soldering unless you used hot air set to 400C for a long time.

[pigrew]

The one mention of this error I found online was where the "security" bits were set to make the device read-only.

I'd suggest re-checking a few of the silly minor things: Is the st-link firmware updated? Are all the Vdd and Vbat and Vdda connected to 3.3V? Is your linker script correct for the F030 (i.e., is the memory mapped to the wrong location)? Do they have decoupling caps near the pins?

STM32CubeProgrammer or ST-Link utility might be helpful for debugging the connection issues. Check if the security bits are set? Try erasing the device in CubeProgrammer?

If you post your schematics, then we might be able to see other issues.

But, yeah... replacing the IC might be a good thing to try.

[panoss]

I replaced the IC (works fine with the new one) as this was the less time consuming action I could take.
Though I will try your suggestions in another board with this IC.