Issue with Powering nRF9161 DK

[sgordon291]

Dear Nordic TS,

I'm trying to power an nRF9161 DK with a simple external battery.  According to the documentation, I thought that this battery voltage should be applied between VIN 5V and GND and that this voltage must fall between 4.0 V and  5.5 V.  My battery back's voltage is 4.75V.  Pls confirm that this is correct, or let me know what the correct info is.

I have confirmed with a VOM that the unit does see 4.75 V between VIN 5V and GND.  In addition, I have verified that the battery can supply the needed current by tesing the battery's voltage across a 500 ohm resistor.   When I make the connection and turn the unit's slide switch to ON, the unit does not appear to boot.  All LEDs remain dark.  

I'd appreciate know (1) have I made the needed and proper connections to power the nRF9161 and (2) are there any steps you suggest to troubleshoot this.

Thank you.

Best,

Steven Gordon

[WesC]

Steve;
The DK is primarily powered by 5 V from the USB connector J6. Alternatively, the DK can be powered by the VIN 5V pin located on the P20 header. Both sources support voltages in the range of 4.0 V to 5.5 V with a nominal voltage of 5 V. The DK must be powered by only one source at a time.

[sgordon291]

Wes,

I saw that in the documentation.  But I cannot get the power to work through the VIN 5V pin on the P20 header.  For a test, I used a USB charging block that has an available current of 850 mA and verified that the charging block voltage is 5V on an open circuit. Then  I connected the power wires of the charging block to VIN 5V (on the P20 header) and GND.  When I do this and turn the unit on, the voltage from VIN 5V to GND drops to about 3.5 V, and the unit shuts off.

I don't understand the reason for this voltage drop, and I think it's causing the unit to fail on startup.

Do you have any insight to what is happening?  If a conversation is a better idea, pls let me know.

Thank you.

Best,

Steven Gordon

[WesC]

try and connect the GND to either P22 or P1.  Dont use the GND on P22 and let me know if that works

[WesC]

Sorry i meant don't use the GND on P20 

[sgordon291]

I finally got this working with one of the 9151s using the P20/VIN 5V post  and P16/GND or P1/GND.  It works with the current from an external USB battery, but run through this terminals, not the USB connector.  Next I'll try powering it with the solar board.

BTW, along the way, I think I killed our 9161.  I think I sent 5V to terminals that should not have gotten this.  Oh, well.  Thanks for supplying the 9151s!