I have a psc2210 and after a paper jam the printer carriage remained stuck and, like your printer, it continued to tell me that there was a paper jam.
I went through the HP online fault finding to no avail and phoned HP. They just tried to sell me a new one. In the end I took it to a local shop that repaired all forms of printer. They initially thought it was the sensors that had become misalined but eventually they tracked it down to being a ball-bearing that had 'popped' out of its socket. To mend it, they had to strip the printer right down. It took about an hour and a quarter. Total cost under £50.00.
Hope this is of some help. Good luck.
Stephen
January 2005