nRF51822 showing short in power after it is first powered on a custom board

[deepu]

hello,

We have developed a custom board corresponding to mbed pca10024 evaluation board.We haven't mounted the rf section and not even the crystal.The only thing that the board contains as hardware is nrf51822 IC,capacitors at AVDD,VDD.Then we tried programming the board using JLink-edu in keil and programmed it with "blinky example" provided by nordic.The programming was successful with led connected at a gpio pin started to blink for few seconds,and suddenly it stopped .When we checked the board it shows short in power.This happens for every board for which board detection and programming is successful for the very first time it is tried and then shows short in vcc and gnd

please help us sort out this issue

[joric]

Same issue on E73 module with this board, DCDC (10uH inductor) as well. https://github.com/joric/nrfmicro/releases/tag/1.2 Soldered the module, flashed with the test application and VCC to GND is now shorted. Desoldered the module - still shorted. Desoldered the 4.7uF cap on the VCC bus - still shorted. Either it's one of the smaller capacitors or the MCU itself. It happened only once with the particular type of board. I blame High Voltage mode (it was the only board that's designed to use internal LDO as well just like yours and it was the only one that fried). The second board worked fine though. I guess I accidently shorted 5V to VCC but I'm not so sure now. Desoldered and checked large 0402 caps they seem okay. Desoldering and checking 0201 ones seem problematic because they're so damn small.  I'm really interested in how your story ended, can you give an update?