Posts: 174
Threads: 32
Joined: Apr 2006
The problem is most likely that the gold plated contact located where the charger plugs in is not properly short circuiting the two posts it is touching. Try and pry the contact away from each post and remove any debris and clean with alcohol or contact cleaner. If it is corroded here, you may have to use some sand paper. I guess it is also possible that a wire is loose from the battery connections inside the calculator.
Posts: 32
Threads: 9
Joined: Jan 1970
If the problem is the contact plate at the charger plug-in point, you can aslo check this by jumping across the two outside charger posts with a wire. This would duplicate the function of the gold contact. If that is the problem, the cleaning should do.
Alternately, I had a similar problem with my HP-65. When I bought it the battery pack was bad, so I rebuilt it. Therefore I knew that it was good. Yet when I put it in, the calculator wouldn't run off of it. I found that if the battery pack was in to far it didn't work. I determined this by putting in the battery pack without the battery door, and then turning it right side up on my hand. As I lifted up slightly on the calculator it started working normally off of the battery pack.
The final solution was just a strip of paper, the length battery compartment, folded up until it was 1/8" wide by 1/16" deep. Once this was underneath the top of the battery pack, the door could be put on and it has worked normally ever since. Hope this helps.
Posts: 12
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Joined: Jan 1970
OK, now I think I understand what you guys are talking about. I looked at my HP-55 and I saw the springy connector tabs that get pushed out of the way when you insert the charger plug. I assume when you unplug it they then make contact with the two outer posts to complete the circuit? If this is true, then I assume the HP-65 should look the same way? If so, the news is not good--it looks like this 65 was taken apart previously and maybe the connector plate was lost or damaged because I see nothing in the 65's charger connector area that looks like what is in the 55's connector area. Any ideas on how to fabricate a connector plate?