This is the procedure to partly disable onboard led’s. Currently this script only disables wireless and lan lights (Power and USB are still on).
Under Administration-> Scripts-> Init tab copy and paste this code:
et robowr 0x00 0x18 0x1e0
et robowr 0x00 0x1a 0x1e0
wl -i eth1 leddc 1
wl -i eth2 leddc 1
This was tested on Tomato Firmware 1.28.0000 MIPSR2-105 K26 USB AIO-64K