|Re: HP-67 Card Reader Motor, techniques and replace the clutch while you are there!|
Message #3 Posted by Geoff Quickfall on 12 Nov 2008, 11:19 a.m.,
in response to message #1 by Stefan Vorkoetter
I have repaired several of these calculators including Namir's 65 and 67 as recently as yesterday!
NO! the adapter does not supply the correct current to run the card reader separately. You must have good rechargeables in the calculator,
Once I have the pinch roller and clutch replaced; always replace the clutch with the pinch roller as, in time it WILL fail once the pinch roller has been replaced.
With the rear shell removed, I apply a three volt current to the motor contacts with a card in place to confirm the card will travel
place a battery pack in the holder of the calculator insuring the gold clip is in place at the adapter contacts
using an external battery pack and clips apply the clips to the contacts in the battery holder of the calc observing the correct polarity (see picture and by the way, use nicads not alkalines as I did in the picture!)
REMEMBER, the white axle has an assymetric fitting on the pointy end of it, this is used to raise or lower the pinch roller to allow the card to be pressed correctly against the card reader head. For example, after fitting the new pinch roller in Namir's hp 65 I kept getting error on about 80% of the card passes. By adjusting the axle with the rear shell off, using the slot in the end of the axle I raised the pinch roller enough to have 100% reliablitiy on the read and write function.
1. if you don't have a battery pack, make one as pictured using nicads!
2. you can check the motor function by applying 3v to the motor contacts.
3. adjust the pinch roller height with the white axle by turning the axle using the slot for applying the twisting moment. I bent a screw drive tip 90' to allow access to the axle when the slot is hidden by it's orientation.
Edited: 12 Nov 2008, 11:21 a.m.