SCART HDTV vs RCA TV power comsumption

I'm a software engineering working with a Set Top Box (STB) which has
both SCART HDTV and RCA TV connectors.  I think I am having a power
problem with the STB when I connect a wireless NIC into the USB port. It
works great in RCA TV mode, but when I use the SCART HDTV settings, the
STB reboots when the USB device is initialized.  I think that there is a
significant power drain in the system when the wireless NIC initializes
the transceiver. I also think that in HDTV mode, the power drain causes
the STB to exceed some critical threshold which causes a reset.  Can
anyone point me to the right direction to information about the power
consumption of SCART vs RCA?

Thanks,

((&->