HP67 Card read error

[yarravalley]

Serial number is 19105003751 or 1910S003751 (bit hard to distinguish 5 and S - Thanks Edwin). Marcus, would expect that the cards from the Standard Pac would work but none of them do (checked them all). Checked writing a small program to a blank card. Worked initially, including reading back in memory but now I can only get it to work about one of of five times. At the end of the read i can vaguely hear the sound of a small metal spring, but that may be normal.

Regards
Marcel