All works!

Note: A very similar device (ASPIRE 5736Z-4085, look up the entry) has been reported that comes with a Broadcom Corporation BCM43225 wifi card which does NOT work with free software.

I notice that it was working perfect with this videocard with some old trisquel version. However, at Trisquel 5.5 and 6 appeared a problem which left the screen black. nomodeset kernel parameter was leaving the computer usable, but aspect relation was erroneous and it was a pain to watch the screen. I found a solution. Use the parameter "acpi_osi=" and increase brightness pressing brightness buttons after grub and the light will be returned returned. I'm using succesfully this on Trisquel 6.0 and I can use the laptop comfortably and with 3D acceleration.