AnsweredAssumed Answered

Custom STM32 board bootup problem - Fried MCU? Help!

Question asked by MrStive on Apr 17, 2013
Latest reply on May 2, 2013 by MrStive
Hi All,
I have made a custom board with the STM32F405.
When I apply power to the board, the MCU is drawing lots of power (like ~200mA+!). I haven't loaded any code onto it, its straight out of the box.

I have 2.2uF caps on VCAP_1 and VCAP_2 and they read 3.3V (Vdd rail). I think this is incorrect and tells me the chip is possibly blown? Possibly from ESD during fitment (baked reflow oven). I hope this is an rare and freak occurrence, is there any way of testing if its dead?
MCU gets no response from ST-Link SWD, with IAR sometimes returning "No MCU Device found", or "Failed to load flash loader".

Some other potentially useful information for diagnosing:
This is my first STM32 board, I mainly copied the schematic from the F4Discovery.
I have BOOT0 and BOOT1 on jumpers to change between GND and Vdd. Have tried all boot configurations with these pins.
I am using PC13/14/15 for IO. PC14&15 drive LEDs, PC13 drives a PNP and is tied high through a 47kohm resistor and base resistor - is this okay?
PH0/1 are not connected
NRST is tied to 5V with 47k resistor and 100nF to gnd+tactile switch.

All Vdd are decoupled <1cm
Vref uses an external reference chip + decoupling
Vbatt is connected via jumper to Vdd + decoupling

Some of the pins are outputting weird voltages. For instance, with Vdd=3.3, Pin51 (PB12) is outputting 2.5V.

I think its dead... Any thoughts?
Thanks for any help in advance!!

Outcomes