Hp-41C card reader - dead

[Vintage63]

thanks to Tony for showing me were the trimmer is!!! I tried changing the position of the trimmer but nothing improves. Rotating it counter clockwise it goes faster and the card advances with a ripping noise, i.e. not fluid. Rotating it clockwise the movement is fluid but still get the MALFUNCTION message. Only once I got a "RDY 1 OF 1" message but never got it back. Hopelss :-(