HP Forum Archive 14

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HP41 rechargeable pack repair Message #1 Posted by Giuseppe Marullo on 31 Jan 2004, 5:42 a.m. Hi, I got a NiCd pack, almost surely dead. I would like to repair it, but I can't find a safe way to open it without breaking the plastic enclosing. The same apply to doubling a X-Memory module, should I break the enclosing for sure (like Cristoph says in his book) using a knife, or a lower impact approach exists? I have another repair to try, a card reader that works well, but one spring on the lock mechanism is not working. Is it worth to try to repair or better to leave as is? Giuseppe Marullo

Re: HP41 rechargeable pack repair Message #2 Posted by Paul on 31 Jan 2004, 8:18 a.m., in response to message #1 by Giuseppe Marullo I have repaired several HP-41 battery packs. I have tried using an exacto knife and an exacto saw. In my opinion, the saw works much better and gives you a nicer looking finished product. I have refit the batteries with 1/3 AAA NiMH (nickel metal hydride)soldered in series. Glue the finished pack together with airplane glue. Paul.

Re: HP41 rechargeable pack repair Message #3 Posted by Giuseppe Marullo on 31 Jan 2004, 12:30 p.m., in response to message #2 by Paul Paul, thank you for your answer. Do you have any photo about the hack? I would like to see an example on how to cut it neatly, this things are not easy to find. The same apply to the X-Memory modules? Do I need to cut the envelope, no other way?

Re: HP41 rechargeable pack repair Message #4 Posted by Vassilis Prevelakis on 1 Feb 2004, 10:11 p.m., in response to message #3 by Giuseppe Marullo Pictures shown the opening up of a memory module may be found at ji's web site: http://www.tla.org/hp41/module.html I'd also use an exacto knife to create the line where the two parts will separate (i.e. don't try to cut through, just create a single continuous scar along the joint, the plactic will open up like a broken zipper once you apply pressure with the blade as shown in the pictures). **vp

Re: HP41 rechargeable pack repair Message #5 Posted by Giuseppe Marullo on 2 Feb 2004, 6:23 a.m., in response to message #4 by Vassilis Prevelakis Vassilis, thank you about the link, I will try it. Thanks to Paul, I find the courage to open the battery pack, I will post photos this evening. I am buying the 1/3 AAA 120mA/h batteries, since the 220mA/h I got are too big for the rechargeable pack, given I will keep original electronic and connector.

Re: HP41 rechargeable pack repair Message #6 Posted by David Smith on 31 Jan 2004, 12:30 p.m., in response to message #1 by Giuseppe Marullo I slice around the joint between the two case halves with a single edge razor blade. This can be rather difficult and time consuming (and a bit dangerous). A saw is easier but can remove too much plastic.

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