Help with HP65 card reader

[isanchez]

Dear all,
I have replaced the card reader roll of an HP65, like I have done in many.

It worked fine during the first 10 or 11 tries, then stopped, then worked another ten times and definitely stopped. NO reaction at all of the card reader when I insert the card (the 0.00 keeps in its place)
I have tried with fresh batteries and charger support, checked the continuity and verified the motor.
What I have realised is that the top right chip in the card reader board (1826-0158) is hot when I try to do the tests is that normal? could be this chip the reason for the misworking? Would it be possible to replace it?

Thanks to all for your help!

Kind regards,

Ignacio

[teenix]

Check the capacitor mounted on the motor terminals, if it is shorted it will cause over current and heat up the sense IC.

Check the card moves through the reader easily or the increased drag will also increase power dissipated by the sense IC. The motor current should be around 180-200mA.

If you have a bench power supply, you can disconnect and power the motor with that and measure the current while feeding cards through. The operating voltage is around 2.4V

cheers

Tony

[isanchez]

Thanks Tony!


I will follow your recommendations.


Kind regards

Ignacio