trying to restore a friends tablet. She says its an Acer A500 that has Android 3.1 on it. She said she ran an update for it and sense then, it only loads up the ACER logo and stays there. Attempts I have done...

Hold power and volume up, sliding the screen lock on and off. In the top corner, it now says
Erasing Userdata...
Erasing Cache...
It stays this way and never seems to move past this. Have left it on for hours and no change

The other thing I do is hold power and volume down and get a message saying its clearing the cache before preforming an SD update, and cmd recovery. It then seem to be trying to run update.zip from the SD card. It then goes to the android logo and seems to try to run something, then get a "!" in a triangle. Eventually it restarts again and sticks at the Acer logo as always.

I looked into this and found an update.zip from someone that seems to be having the same problems. I preform the same booting as before with an SD card and the update.zip file. I get the exact same results except it seems to go to the "!" much faster.

Any suggestions as to what to do next?