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HP Forum Archive 14

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HP-65 Card Reader "Gummy Wheel Problem"
Message #1 Posted by Dr. Carl P. Loller on 16 Feb 2004, 7:50 a.m.

I have a beautiful old HP-65, which I think has the gummy wheel problem I've heard about. It struggles to pull the card through the reader (the card sticks and the motor runs) and a sticky deposit is left on the top edge of the card.

Is the repair scheme for the HP-65 card reader problem the same as the one shown for the HP-67 or is it different? I'm worried about having a go myself and getting into a mess by removing the wrong screws etc.

Can anyone help with information please?

Alternatively, is there a reputable repairer of HP-65s anyone can personally recommend? I live in the U.K.

Carl

      
Re: HP-65 Card Reader "Gummy Wheel Problem"
Message #2 Posted by Victor Koechli on 16 Feb 2004, 9:37 a.m.,
in response to message #1 by Dr. Carl P. Loller

The instructions for the HP-67 also apply to the HP-65.

Cheers, and good luck, Victor

            
Re: HP-65 Card Reader "Gummy Wheel Problem"
Message #3 Posted by Michael Meyer on 16 Feb 2004, 11:25 p.m.,
in response to message #2 by Victor Koechli

Be careful with the HP-65 repair. The wires leading to the card reader are very fragile, and are soldered directly to the circuit board (as they are on some 67's). I'd make sure to record the location for each color. Good luck, Michael

                  
Re: HP-65 Card Reader "Gummy Wheel Problem"
Message #4 Posted by Randy Sloyer on 17 Feb 2004, 12:29 a.m.,
in response to message #3 by Michael Meyer

Also be careful with the same wires at the head end as well. They used a soft silicone potting compound on the 65 heads, the wires can break off inside the head if twisted too much. They can be repaired but it is a miserable job.

Later heads used a hard potting material and they are a bit more robust.

Edited: 17 Feb 2004, 12:30 a.m.

                        
Re: HP-65 Card Reader "Gummy Wheel Problem"
Message #5 Posted by Victor Koechli on 17 Feb 2004, 4:15 a.m.,
in response to message #4 by Randy Sloyer

Would you recommend desoldering the head before proceeding with the repair, then? That way excessive twisting of the wires could be avoided...

Cheers, Victor

                              
Re: HP-65 Card Reader "Gummy Wheel Problem"
Message #6 Posted by David Smith on 17 Feb 2004, 5:54 p.m.,
in response to message #5 by Victor Koechli

No, leave the wires be. They are a real pain to desolder/solder and you would be moving them around even more than just fixing the roller.

                                    
Re: HP-65 Card Reader "Gummy Wheel Problem"
Message #7 Posted by Dr. Carl Loller on 18 Feb 2004, 3:57 p.m.,
in response to message #6 by David Smith

Many thanks to Victor, Michael, Randy & David for your advice.

Carl


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