Thanks Volt, yes I did initialized it to factory settings and re-installed the latest firmware (DR-70D_b70.114)... but the same... I tried 2 different sets of eneloops, and external power from USB (computer) and the same result... I used the card that always have used, a Sandisk Ultra 8gb (30mb/s) and also a Kingston 4gb (class 4) and still nothing... It turns on, but no monitoring from any input... even starts recording, but no signal, its like the preamps controller just gave up... I dont know...
I'll have to send it back to the reseller for repair, but its quite a thing because I bought it in Europe from a big online store, Thomman, and they'll take 3 to 4 weeks to check it and perhaps send it back to Tascam's.... for further checking..
In the meanwhile I manage a borrowed Dr70D from a friend, same card, same batteries, and everything went smooth...
Don't know... thinking going Zoom F4 if this turns out bad... more expensive, but better preamps, kind of mixer onboard, XLR out, nicer screen, a bit bigger... I really like the size and portability of the Dr70D, but I'm not trusting Tascam again...I don't know when it it will happened again... :-(
Thanks for the advice Volt and F.O.Bean