HP97 printer never turns off

[isanchez]

Dear friends,

I am trying to repair an HP97.
The thing is that when I turn it on, the printer head starts to move and never stops, even when I put the paper roll. It prints nothing, just tracks the head moves and pulls the paper.

I have tried with another (working) printer and still the same behaviour, so the problem is not in the printer itself.

The display shows nothing at all...

Do you have any idea about where can be the probelm?


Thanks and kind regards


Ignacio