HP67 Card read error

[yarravalley]

Just received a beautifully restored HP67 but have a problem reading clipped cards. They all (including the standard pack cards) give an error. Unclipped cards write and read without any problems. Anyone a suggestion?

Regards
Marcel

[Marcus von Cube]

(04-10-2015 11:55 AM)yarravalley Wrote:  Unclipped cards write and read without any problems. Anyone a suggestion?

It's likely some misalignment or motor speed problem. Cards written with the exact same hardware work while cards written by a different mechanism fail. I don't think the clipping has to do with this.

[edwingatox]

What serial number is you HP 67?

Edwin

[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

[edwingatox]

Marcel,

Your HP 67 is a late model. It has a variable resistor in the Card Reader Controller PCB (It's an square piece maybe blue or black) and one tantalum capacitor (rounded). Early models have 3 tantalum capacitors (axial).

Try adjusting the variable resistor. It controls the speed of the motor.

A little adjusting maybe can resolve the problem.

If not, you possibly need clean the head with Isopropyl alcohol or adjust the little screws that controls the switches (last step, be careful).

Best Regards, Edwin

[yarravalley]

Thanks Edwin. Much appreciated. Will give it a go.

Regards
Marcel

[edwingatox]

My mistake: HP 67 Late, 2 capacitors (rounded). Early, three (axial).

Edwin

[yarravalley]

No worries Edwin. Didn't go in with the welding machine and the jack hammer yet :-)