HP-65 card reader - purpose of WE pin

[albertofenini]

Dear all,
we are in the process of restoring an HP-65 thanks to the contribution of one of the members
that has provided a logic board and a cathode and anode driver.

So far so good, we have also began to use the TAMIYA matt finish spray ad the results are very
encouraging as the unit really recover that "like new" finish appearance.

However we have trouble, as often happens, with the card reader.
Waveforms RA and RB are good and the unit reads all of the cards, including those written by other HP65
Waveforms WA and WB are also good and clean, but the unit does not record.

We will perform soon the switch test, checking that the WPS switch closes correctly when the
card is inserted.

However, what is the purpose of the WE pin in the card reader PCB ?
Has it something to do with Write Enable (??) and is a possible cause of malfunctioning ?
How can we check that ?

It also must be said that the logic board is new, the card reader PCB is also new
(I mean is none of the spares we had before that were also not working) but the keyboard
plastic assembly, including the card reader switches on the back and the keyboard PCB are a spare part we had before, and
that we were not be able to use it until now because it was lacking the anode and cathode driver
that we transplanted now from the donated one (that was too corroded to be used)

Any idea or hint ?
thanks for help very much !!