OB8 HELP!!! URGENT!

Dear friends,
I stupidly, as a newbie, bought a OB8 for a friend that seemed to work  
properly when I checked it .
At my return home, I switched it on, tried to save some patches and,  
immediately, all the memories were erased. Moreover, now only the  
lower voice board is heard. The upper has the leds switched on  
sequentially but no sound.
At a more careful check, the U17 IC (RAM) is MISSING!

I have tried to save some patches in the machine, they seem to work.

What happened? Did I have a ripoff? Is the U17 missing normal ?

I have no service manual

Please help me asap, my friend will not pay my money back...

Fernando