Got a HP 19C

[Duane Hess]

(11-18-2016 08:53 PM)david sanz Wrote:  ......
Upon powering up, the display stays dead, but the printer goes mad working non stop. Nothing is printed though ......

It would have nothing to do with the paper or the print head, even if the head was defective.

You might consider the power supplied to the calculator. There have been previous posts (can't identify them) about that behavior being related to the internal power of the 19C as not sufficient.

i.e. corroded battery terminals, internal connectors (the gold finger things) tarnished, etc. There is a connection but the amount of current able to flow is seriously diminished.

I have a 19C with the same problem, internally cleaning all contact points bypassed the problem. Taking a 19C apart is easy, putting it back together is tedious. Aligning the multiple rows of "finger pins" without bending them is bothersome. As I recall, there was a row basically at the top of the keyboard which is difficult align and reach.

Should you be mechanically inclined you might consider a product like Deoxit and clean the battery contacts and internal connections of the calculator. Doing so might restore its operation, you may still have problems with individual keypresses.

Just a thought.