Stm32h7b0vbt6 SWDIO and VCAP are shorted

[Nikos_Chalkias]

Hello, so I have designed a pcb using the stm32h7b0vbt6 mcu. After finishing the soldering process and checking thoroughly for any shorts, I tried debugging the pcb. However there was always an error initializing the St link. So I checked for any shorts and found that swdio pin is shorted with vcap1 and vcap2. Of course my first thought was that there was a short because of the mcu soldering even if there weren't any visible shorts. After cleaning the connections for a while the short disappeared only to appear again after powering up the board. After some thought I hypothesised it was a malfunctioning pcb so I started soldering on my backup. After connecting the mcu and checking for any short circuits, of which there were none, I powered up the board and low and behold, the swdio and vcaps were shorted. I have no clue what could cause this on two separate pcbs and would like some help/advice. I am happy to send any pictures or the pcb layout.

[Tesla DeLorean]

Double check orientation.

Perhaps a large, clear and in-focus picture of the part in-circuit, and salient portion of the schematic.

[Nikos_Chalkias]

Orientation is correct, I have designed and soldered 2 other working pcbs using this mcu.

[Peter BENSCH]

OK, and what about point 2 that Tesla mentioned, i.e. the pictures and the schematic of the relevant part?

[TDK]

> I am happy to send any pictures or the pcb layout.

It would be helpful if you did this. It's almost certainly a hardware error (layout and/or soldering) and you're the only one with access to the hardware.

> After cleaning the connections for a while the short disappeared only to appear again after powering up the board.

Shorts generally don't disappear temporarily. How exactly are you determining it's a short and that it disappeared/came back?