nrf9160 Pins 104-127 functions?

[sethkaz]

I'm currently working with a client who is implementing the nrf9160 into their product.  They had a version of PCB made which connects pins 104-127 to ground, even though the datasheet says to leave them floating.  

As I'm trying to power up the chip, I'm seeing it draw a significant amount of current 200-400mA, and it begins to get warm.  Also, it cannot be programmed.  

What I'd like to know is:  Would grounding those pins cause that behavior?  Or should I continue hunting for other issues with the board?

[helsing]

Hi Seth,

Yes, modifying the board so that pin 104-127 are floating would be a safe place to start. The pins have various properties and some of them certainly should not be grounded.

In any case. Please be aware that Nordic is offering free hardware design reviews. If you upload schematics and PCB design files we could review the part of the design that is related to the Nordic parts.

Best regards,

Håkon

[sethkaz]

Hi Hakon,

I'll do what I can.  Any suggestions on the best way to de-solder the 9160?

I will make sure that others take advantage of that free hardware design review in the future.  

-Seth

[helsing]

Hi Seth,

sethkaz said:

Any suggestions on the best way to de-solder the 9160?

Have you checked with your manufacturing/prototyping company?

sethkaz said:

I will make sure that others take advantage of that free hardware design review in the future.  

If you like, you may start with this design.

Best regards,

Håkon

[helsing]

sethkaz said:

Any suggestions on the best way to de-solder the 9160?

Here is some feedback I got regarding de-soldering: You may remove the SIP with an under-heater and then an airgun. This works well but the pads can come loose if you try to lift the device too soon before all the solder has flowed properly.

I will let you know if I find more information regarding de-soldering.