EC200UCN Flash Error

Technical Subjects Open Solution
1

Hi - Currently we are into production mode using EC200UCN and QuecOpen

Out of 1500 nos under production atleast 75 nos. of Modules are not showing the Comport -

  1. We are connecting USB to Module pin No. 69 to 72 for programming - What can be the reason and remedy for this?
  2. We are using Nor Flash on SPI port Module Pin No. 37-40 - Some of the devices (atleast 20 nos) are giving Error while programming Prepack files to module.
  3. To rule out error of NOR Flash → We have checked PCB connection to and from NorFlash to Module and also tried replacing NOR Flash of the Error PCB to working PCB and its getting programmed

Request your guidance on above hardware issues related to Module.