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TMDXSK437X: Neither Processor/DDR work after they are replaced/ reworked

Part Number: TMDXSK437X


We are using a TMDXSK437X as our reference to build prototypes. We noticed that in many prototypes, when we try to replace either DDR or Processor, the other IC doesn't respond.

Example situation: If we have a PCBA with AM437x processor passing the JTAG tests and DDR IC not working board (which might have due to some short or something), We get it replaced with a new DDR IC using a OKI BGA rework station. After the rework done on the PCBA, the Processor will not be able to even pass the JTAG test which was previously passing.

Similarly if Processor has to be replaced due to some internal short, We get it replaced and test it. It passes the JTAG test but now the DDR3 will get effected and it will not pass the DDR test.

I would like to if anyone has faced a similar situation like this. Please help us out in restoring the PCBA.

Note: We have faced this problem with AM335X and DDR in another prototype design too. We think this may be a thermal profile used for the replacing the BGA packages. 

Is there any other suggestions how to over come it? Is there any particular thermal profile that is suggested for TMDXSK437X reference design to replace DDR3/ AM437x?

Did anyone else face such kind of problems?

Best Regards,

Aditya Teja Damera

  • Hi Aditya,

    Generally, we send our boards to an assembly house to replace nFBGA components.  Removing and cleaning the board is important to success.  In addition you will have check that the solder mask around each of the pads has not been damaged to ensure that shorts will not be created.  

    Attached is the package appnote for the nFBGA package.  This document include recommended reflow profile information.

    Regards, Bill