HP Forum Archive 21

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41CV from craigslist Message #1 Posted by David Persinger (US) on 12 June 2012, 11:06 p.m. I have my first opportunity for some vintage calculator restoration... I saw a 41CV advertised on Craigslist for $50. When I went to get it I saw the contacts were corroded. I removed the corrosion I could but it would not power up with new batteries. I bought it for $20, thinking maybe I could get it working somehow. The foil is corroded back to the connector on one side but the contacts to the main board themselves look good. what is the best way to get this fixed? Find another non-working donor which has no corrosion and swap out the back? Solder a wire from the connector to the battery compartment? Or is there a way to repair the foil on this one? I know there is some info in other threads, but I find it terribly difficult to search the forum. I appreciate any advice on this...

Re: 41CV from craigslist Message #2 Posted by Gerson W. Barbosa on 12 June 2012, 11:21 p.m., in response to message #1 by David Persinger (US) Quote: I know there is some info in other threads, but I find it terribly difficult to search the forum. Easily done if you use Google (not an advertising!). Using site:www.hpmuseum.org HP-41 fixing battery contacts as the search key, for instance, returns 1000+ hits. Stefan Vorkoetter's great article appears to be what you are looking for: Repairing an HP-41CX Good luck!

Re: 41CV from craigslist Message #3 Posted by David Persinger (US) on 12 June 2012, 11:37 p.m., in response to message #2 by Gerson W. Barbosa Thank you. Also for showing me how to limit a search to a specific site. Didn't know that... I've always tried using the archive search with mixed results. Edited: 12 June 2012, 11:54 p.m.

Re: 41CV from craigslist Message #4 Posted by Ignazio Cara (Italy) on 13 June 2012, 4:13 a.m., in response to message #3 by David Persinger (US) I can only confirm that the contacts foil purchased from Diego are the best for this kind of restoring. I've restored ten or more block contact with complete success. Be confident Ignazio

Re: 41CV from craigslist Message #5 Posted by Diego Diaz. on 12 June 2012, 11:37 p.m., in response to message #2 by Gerson W. Barbosa Hi David, You may want to have a look at my web page regarding the I/O Flex PCB here.. If you think this can be useful, please contact me privately to "clonix41(at)gmail(dot)com". Cheers. Diego.

Re: 41CV from craigslist Message #6 Posted by Geoff Quickfall on 13 June 2012, 12:03 a.m., in response to message #5 by Diego Diaz. Having used Diego's flex I/o to restore three battery/module blocks I can certainly recommend them. Cheers Geoff Edited: 13 June 2012, 12:03 a.m.

Re: 41CV from craigslist Message #7 Posted by Kerem Kapkin (Silicon Valley, CA) on 13 June 2012, 12:09 a.m., in response to message #6 by Geoff Quickfall +1

Re: 41CV from craigslist Message #8 Posted by Diego Diaz. on 13 June 2012, 12:39 a.m., in response to message #7 by Kerem Kapkin (Silicon Valley, CA) Hi Geoff, Kerem, Thanks for your support... :-) BTW Geoff, I'm (as many others) waiting for your book; this is not intended to hurry you up whatsoever... (I know quality needs time :-) just wanted to know if there is a procedure to join the waiting list which I may not be aware of. All the best from Caribbean Sea. Diego.

Re: 41CV from craigslist Message #9 Posted by Geoff Quickfall on 13 June 2012, 12:48 a.m., in response to message #8 by Diego Diaz. Email me and I add your name to the list. Your name is actually on the list due to your 41cx CLONIX and flex I/o help. Cheers, Geoff Looking at compleetion for HPCC 2012 Edited: 13 June 2012, 12:49 a.m.

Re: 41CV from craigslist Message #10 Posted by Randy on 13 June 2012, 8:11 a.m., in response to message #1 by David Persinger (US) If the traces are okay at the keyboard side connection, you can cap the damaged connection points with short lengths of 1/8" brass u-channel (available in most hobby shops). If the damage to the ends is worse than the one shown, and you cannot solder the cap on at the edges of the foil as shown, you will have to scrap away the coating, down to the copper and then solder both top and bottom areas. The top area to solder is shown circled in red. Duplicate on the bottom. The bottom connection connects the circuit, the top just helps to hold it in place.

Re: 41CV from craigslist Message #11 Posted by David Persinger (US) on 13 June 2012, 10:37 p.m., in response to message #10 by Randy Thanks, Randy. I don't have a good way to post a photo right now, but the corrosion runs up right next to the contact with the main board. I doubt there is more than 1/32" good foil just before the contact point with the board. It is a real mess. I went ahead and ordered a new part from Diego. Hopefully that will come in soon and I'll be able to replace the whole piece. Thanks for all of the input! David

Re: 41CV from craigslist Message #12 Posted by aurelio on 13 June 2012, 5:26 p.m., in response to message #1 by David Persinger (US) David, what is the "Craiglist"? ...apologize for my ignorance, but, I don't know what do you mean Cheers Aurelio

Re: 41CV from craigslist Message #13 Posted by BobVA on 13 June 2012, 9:40 p.m., in response to message #12 by aurelio Quote: .....what is the "Craiglist"? It's a very popular collection of US local "for sale" websites. Sort of like classified ads in a local paper - deals are typically person-to-person for items but ads also cover things like apartments for rent, etc. Edited: 13 June 2012, 9:42 p.m.

Re: 41CV from craigslist Message #14 Posted by Les Wright on 13 June 2012, 11:14 p.m., in response to message #13 by BobVA It's actually worldwide. Aurelio, here is Craigslist in Rome. Edited: 13 June 2012, 11:16 p.m.

Re: 41CV from craigslist Message #15 Posted by aurelio on 14 June 2012, 3:06 a.m., in response to message #14 by Les Wright Bob, Les, Thank-you From a place you can surf to the other towns I see...interesting Aurelio Edited: 14 June 2012, 3:19 a.m.

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