This is the way that revived me so dead TP :
I charged for at least 15 hours the TP with a handsfree mini USB charger at 5v, 0.7mA (instead for the original TP charger of 2mA).
Then I holded the power button and pushed rapidly 15-20 times the home button.
I did the opposite holding the home button and pushed rapidly 15-20 times the power button.
I really do not know which one of these two combinations make the TP wake up.
After two-three minutes after my attempts the plug icon appeared on the screen and I rapidly connected with the original TP charger via cable. Home button was glowing for first time after days.
After half an hour moboot menu appeared and I choosed fast to boot on the webos. That's it !!
It now is charging on webos nice and easy. To be sure that I am not going to live this situation again I choosed to boot on Webos by default instead of ICS through Cyboot.
Till these wonderfull guys stabilize the ICS for the TP use cyboot to avoid such problems.