I accidentally closed the original ticket, so I create a new one.
Hi,
recently I'm building dfu function on my board, using nrf51822 qfaa and softdevice s110.
( Keil v5 to compile and SDK 10 to build bootloader, SDK 7.2 to build application )
Here is the situation. I get two 51822 modules:
-one is Raytac MDBT40, using nRF51822 QFAAH00, called A
-the other I'm not sure, using nRF51822 QFAAH10, called B
From Nordic document, the x in the build code is 0..9 for production release.
At first, I run dfu_dual_bank_ble sample code on 51DK. Here is the original bootloader address:

I got B module earlier than A. I change to custom board and change address:

It works well on B.
Then, I repeat the steps on A module. The same bootloader can be loaded to A, but it can't work, even advertising.
I've checked if I only load s110 and application, it works.
Is there something I misunderstood or miss checking?
Thank you very much.
Edited:
At the very beginning, Raytac module has bootloader inside (attached image), and the other is totally empty. I do erase the memory before download into them.

Other questions:
1. What does "0x0072", which is listed after QFAAH00 in the image, mean?
2. Bootloader doesn't work without softdevice, does it?