Read?Write HP 67 card reader

[Geoff Quickfall]

After:

1) replacing two key snaps with a donor snaps from a dead 55 harvested board.

2) replacing the dampening couple with a silicone and insulation repair.

3) Replacing the pinch roller with a milspec silicone tubing.

4) cleaning the keyboard bezel, re-lacquering it in flat clear.

5) cleaning the keyboard and logic PCA connections.

The calc writes. Card tested in working 67. The calc does not read it’s own cards or any others producing the standard Error on each read.

The current draw on the card reader is correct. The card reader head reads and writes with a known functional spare board swapped for the suspect board which is pictured.

Apparently, with searches, these two caps are suspect and may not have the correct ESR. Before diving into a de-solder and etc. what are the replacements. Are they polarized, would smd mounted tantalums be viable or electrolytic.

At the moment looking at 16v 47uF and 22u F to replace. See picture.

Any help would be appreciated. This is for the BOOK!