Battery contacts on Classics

[bshoring]

(04-08-2017 02:49 PM)rprosperi Wrote:  

(04-08-2017 04:05 AM)olr Wrote:  When the machine is powered by battery, the left and right pin for the wall plug (the two lower ones in your picture) must be shorted. Maybe the responsible "spring" fails to make contact.

Agree, this is often the problem. Once you are sure the left and right pins in the charger socket both make contact with the metal plate, try cleaning the area where the pins contact the plate with DeOxit (or a similar) contact cleaner.

Edit: Looking again at your photo, there is indeed evidence of oxidation (greenish spots) on the metal plate that connects the left and right pins when the adapter is not installed, so this likely is the issue.

If this does not work, I'd say Tony is right there must be damage inside, which is odd as those battery contacts look as clean as new. While the contact cleaner is handy, also clean the battery contacts (both the contacts in the machine and also on the battery), oxidation is still possible even though they photograph well.

Thanks, OLR and Bob! You hit the nail on the head. Oxidation and/or dirt kept the springs from the metal plate from making contact with the pins. First time I applied DeOxit nothing changed. Then I applied again and used a small piece of cardboard and moved it around between the springs and the pins. Then when I inserted the battery pack, it worked ! I attach a photo of what it is supposed to look like, in case someone else encounters this problem.

I'm a happy camper now. Thrilled that I don't have to open up my near perfect HP-80. BTW the seller apparently was not into electronics and shipped the calculator with the adapter cord still plugged into the unit. I have a feeling it's been stored that way for years if not decades. The seller sold it "as is" as he/she was not even sure if it was fully functional. But I've run through the manual and everything computes perfectly.

It is so great to have this wonderful forum as a resource!