It is possible that you may have blown out the TFP410 by plugging it in with power applied to the Beagle. What model of display are you using? We have had a few cases where some displays are more particular than others. While a board may not work on one display, it does on others.
I try the factory default kernel, but initial display from Uboot still
doesnt displayed. I try it with severals DVI computer monitors (ACER,
SAMSUNG, TEAC). Input pins of TFP410 looks good, but output TXD pins
of TFP410 are pernamently at log. 0.