I have two custom PCBs, each of which has a microcontroller and an nrf24L01+. Everything related to the transceiver in the designs are complete duplicates (with the exception of the CE pin, which goes to a different I/O port. I have confirmed that this is not the problem, however). I have loaded the identical program onto both, which directs the NRFs to transmit 9 bytes of data over channel 7 with auto-ack enabled. On one board, everything works as it should; the micro sends the data over SPI, the NRF transmits the data, replies to the micro that it has transmitted, and I can view the packet being transmitted on a spectrum analyzer. When it's transmitting, the VDD_PA pin toggles, the external 16mhz crystal oscillates, and there is no voltage on the DVDD pin.
However, on the second board, if I attempt to do the same, the micro still transmits the data over SPI, but the NRF never transmits (cannot view the packet on spectrum analyzer), and never says that it's finished transmitting. The VDD_PA pin does not toggle, and the external xtal does not oscillate, and very strangely, 1.57v can be seen on the DVDD pin continuously. We have tried changing boards (ruling out a manufacturing error), tried changing NRF ICs (no change), tried changing oscillators (no change), tried tweaking load capacitance (no change).
Any assistance as to possible causes for this would be greatly appreciated.