HP-65 goes on hold after reading a card

[teenix]

(11-30-2020 02:25 AM)Kostas Kritsilas Wrote:  I don't believe that the person attempting the repairs used an oscilloscope, as his background is in chemical engineering. He said he did inspect all the traces going into and out of the card reader ICs under magnification, and said they were fine, and verified them with a multi-meter.

He had some spare HP-65 card reader parts, and said that he tried to repair the unit with them, but then found out that the spare units themselves were bad. he also said that he would be putting his own spare HP-65s up on eBay as non-working units. he also said that the HP-67 heads are better in this regard, as they use a thicker, better insulated wiring between the board and PCB.

This is all I have on the repair process. The statements about the read/write head being bad, whether it was the leads going to the head, or the head itself, came from the person attempting to repair the unit. I can forward the relevant emails in direct messages if anybody would like to see them.

What a shame the parts were unusable.

Without an oscilloscope check, it would be hard to define where the problem might be.

On reflection, I guess it is hard to test a card write because you cannot read it back again unless you have access to another 65.

cheers

Tony