The Museum of HP Calculators

HP Forum Archive 06

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HP_41C
Message #1 Posted by Otavio Gaino on 7 Nov 2001, 11:25 a.m.

I am looking for a part for my HP41C. This part makes connection between the "Keyboard" and "Logicboard". Anybody could help me?!?!??

Thanks a lot...

      
Re: HP_41C
Message #2 Posted by Vieira, Luiz C. (Brazil) on 7 Nov 2001, 2:13 p.m.,
in response to message #1 by Otavio Gaino

Hello;

I have once seen (working perfectly) two polymeric contact bars at these positions. If you can find any that fits in, I believe they will work fine too, since MOS circuits do not need so much current. Original contacts are made by flex circuit (just golden plated contact bars) folded over a sort of foam. (I do not think I explained fine; my English knowledge is not enough sometimes)

Let us know if it gets working.

            
Re: HP_41C
Message #3 Posted by Otavio Gaino on 7 Nov 2001, 2:37 p.m.,
in response to message #2 by Vieira, Luiz C. (Brazil)

Desculpe!. meu Inglês não é muito bom...poderia responder em Português... Grato...

                  
Re: HP_41C (english and portuguese)
Message #4 Posted by Vieira, Luiz C. (Brazil) on 7 Nov 2001, 3:40 p.m.,
in response to message #3 by Otavio Gaino

O.K. (Vou escrever em Inglês, também, porque me sinto como um convidado aqui... I´ll write in English too, cause I feel as a guess in here)

I have once seen (working perfectly) two polymeric contact bars at these positions.
(Já vi (funcionando perfeitamente) duas barras de polímero condutor nesses lugares.)
If you can find any that fits in, I believe they will work fine too, since MOS circuits do not need so much current.
(Se você conseguir uma que encixe no lugar, acredito que funcionará também, porque os circuitos MOS não necessitam -não consomem- muita corrente elétrica)
. Original contacts are made by flex circuit (just golden plated contact bars) folded over a sort of foam.
(Os contatos originais são feitos com circuito impresso flexível (barras de contato simples banhadas a ouro) dobrado sobre um tipo de espuma.)
(I do not think I explained fine; my English knowledge is not enough sometimes).

Are you in Brazil? Where? E-mail me. (Tá no Brasil? Onde? Manda um e-mail.)

                        
Re: HP_41C (english and portuguese)
Message #5 Posted by Marx Pio(Brazil) on 8 Nov 2001, 11:13 a.m.,
in response to message #4 by Vieira, Luiz C. (Brazil)

Luiz,

My 41CV sometimes refuses to work without the "brazilian way" solution. I saw 2 contacts with signs of corrosion and everytime I change the batteries I have to accomodate the batt compartment or it doesn't turn on...

Can you help me?

Saudações de Manaus...

Marx Pio

                              
Re: HP_41C (english and portuguese)
Message #6 Posted by Vieira, Luiz C. (Brazil) on 8 Nov 2001, 11:41 a.m.,
in response to message #5 by Marx Pio(Brazil)

Hello;

I know it sounds strange both Brazilian xchanging messages in English, but I believe you understand my point, "certo?"

I also have an old 41CV (1985) that also needs some batteries 'shaking' before turning on. I achieved some better results by soldering two small, thin metal pieces over the contacts (please, don't blame me... the original were about to vanish). I also use commercial metal polisher (in Brazil we have Brasso and Silvo) that chemically clean contacts. After cleanning them, I use micro oil (Tutti, or WD40) with a swab or brush, just to place a protective cover.

I had once to open this caculator, carefully clean the mainboard contacts, use the procedure above and it worked fine for more than 2 years. It is working again (after about 7 years stored) and the contacts were cleaned, ready to work.

If you need something else, feel free e-mailing me.

Cheers from Minas Gerais (treim bão, sô!)
(Kind of That´s good stuff in my place...)

                                    
Re: HP_41C (english and portuguese)
Message #7 Posted by Marx Pio on 8 Nov 2001, 3:46 p.m.,
in response to message #6 by Vieira, Luiz C. (Brazil)

I´ll try to do it the way you did. Wish me luck!

I studied and graduated engineering in Minas Gerais in Itajubá and I miss the quentão and the world´s famous pão-de-queijo.

Thankx for the reply

From the Amazon Jungle,

Marx Pio

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