LPC1857 not booting

[vivekpjohn]

Hai i am using LPC1857 in a custom designed card. I have followed the hardware design of MCB2300. My board was working well for months and suddenly it stopped working. Since it was working alright earlier, i didnt doubt the hardware design and hence made 4 more such boards. But now none of the boards are working/booting. In JTAG ( i am using both keil ULINK2 and Segger JLINK with KEIL microvision IDE) the core/cpu is not getting detected now. Also, i am not able to get any clock signals in the XTAL1 & 2 pins to which i have connected the 12MHz crystal. Even i tried giving an external oscillator signal to the GP_CLKIN but still not booting.

Can anyone help me out to solve this issue?

[vivekpjohn]

Hai,

The microcontroller core got detected when i selected SWD instead of JTAG  in the KEIL IDE. But earlier when i was using the prototype board, i was working in JTAG mode. DOn't know why it is not working in JTAG mode now and only in SWD

[bernhardfink]

• Use boundary scan to check if the device in general is somehow alive
• Measure the power consumption of a defect board and compare it with a working board (for example when you hold both boards in reset)
• Remove the chip, reball it and put it into a socket board
• Talk to your distributor if a quality return of such a defect device is an option

[vivekpjohn]

Hai,

Thanks for the reply. 

Can you please tell me how to perform the boundary scan test? Is it possible with the JTAG?

Thank you.

[bernhardfink]

I googled for "jlink boundary scan", these are just the first 3 links which I think could show something useful:

How to do a simple JTAG (boundary) scan? - J-Link/Flasher related - SEGGER Forum 

Debugging using Segger J-Link JTAG - Boundary Devices 

JTAG chain & testing