NodeMCU ESP8266 Ver 0.1 not powering on with VIN
Interesting problem. The input range for Vin is 5.5 to 10 volts. This link will give you more information: https://www.make-it.ca/nodemcu-arduino/nodemcu-details-specifications/
I would not venture to guess that your board is OK, since you short pins all kinds of nasties can happen. Also you do not state your reference point for your voltage measurements so I assume it is ground but the readings do not appear correct. How are you 100% sure that the USB charger is working, providing 5V, and that the ground and VIN are connected to the right positions. Did you measure it with the load connected? Can the charger output the voltage at the current you require?