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HP Forum Archive 14

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HP-67 w/melted Battery Compartment Door
Message #1 Posted by Paul Brogger on 8 Dec 2004, 5:47 a.m.

I just picked up a 67 with neither a charger nor a battery pack (so I'll be looking for those . . .)

The calculator is in generally VERY good condition, except for the heat-distorted battery compartment door -- a distortion which unfortunately extends (only very slightly) to the back case of the calculator itself.

A new battery cover will almost entirely solve the cosmetic problem, but can anyone venture a guess as to what that says about the electronics?

Edited: 8 Dec 2004, 2:34 p.m. after one or more responses were posted

      
Re: HP-67 w/melted Battery Compartment Door
Message #2 Posted by Jeff O. on 8 Dec 2004, 8:02 a.m.,
in response to message #1 by Paul Brogger

What is the condition of the compartment itself? Is there any melting/distortion, etc.? If the case below the compartment has only slight damage, and the compartment has little or no damage, I'd guess the electronics are OK.
Good to hear from you again Paul.

NO60hzSPAMatFORieeedotMEorg (remove NO SPAM FOR ME and change the at and dot.)

            
Re: HP-67 w/melted Battery Compartment Door
Message #3 Posted by Paul Brogger on 8 Dec 2004, 2:45 p.m.,
in response to message #2 by Jeff O.

The interior of the battery compartment looks fine. The heat distorted the upper outer edge of the compartment opening, near the rubber foot, roughly opposite the "A" key. Other than that, it looks great.

I fixed my 97's card reader, so I guess I'll be working on this one, sooner or later.

BTW, the serial # on this seems to have been mis-struck -- I can only make out the digits "...81552" between the upper feet -- and at a weird angle no less (not quite parallel to the case-bottom's "folded" edge). Curious.

But, with a replaced back case & battery cover, this thing may someday qualify as "near mint".

            
Re: HP-67 w/melted Battery Compartment Door -- It Works!
Message #4 Posted by Paul Brogger on 14 Dec 2004, 11:35 a.m.,
in response to message #2 by Jeff O.

A generous soul offered the use of a charged battery pack, and the thing works GREAT! (Even the card reader, after a few runs through, reads a short program successfully.)

(I think I've got a new favorite.)

I do have a question: Is it possible the process of charging the pack in the calculator is what caused the battery cover to melt? (Even the back case is a bit distorted along the "latch edge".)

Maybe it would be best to charge the battery pack elsewhere -- say, in my 45? (Which as well, by the way, I found out works now that I have a battery pack to play with.) I just don't want risk any more damage.

But, hey! I'm happy! Merrrrrry Christmas!

                  
Re: HP-67 w/melted Battery Compartment Door -- It Works!
Message #5 Posted by Jeff O. on 15 Dec 2004, 7:28 a.m.,
in response to message #4 by Paul Brogger

Paul,
Good news about your 67.
Regarding the original cause of the melting, in my marginally educated opinion it probably was caused by an overheated battery. However, I think it was likely a one-time event, caused by a defective battery or perhaps a defective charger. The manual states (Appendix B, page 311 of the Revision C, 12/76 manual):

"If desired, the HP-67 can be operated continuously from the AC line. The battery pack is in no danger of becoming overcharged."

If you use the calculator normally, it should be safe to charge it up in the calculator. Of course if you have some way to charge it externally, that would provide an added measure of safety. Just don't forget that the pack is out and run it off of the charger without the pack, as the manual also states (page 312):

"CAUTION Operating the HP-67 from the ac line with the battery pack removed may result in damage to your calculator."

Edited: 15 Dec 2004, 1:31 p.m.


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