The Museum of HP Calculators
HP Forum Archive 05
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|Cathode Driver Question for Classic Calcs|
Message #1 Posted by Mike on 4 Mar 2001, 5:05 p.m.
I once found an article on the classic displays. I have searched and searched and cannot find the link to that article.
In it, it mentioned the types of driver chips used in the various classic models. I think I have a cathode driver problem in my 65. The 13th digit does not light ('-' sign) and I have eliminated the LED as the source of the problem. I suspect it is the cathode driver (digit drive).
The part is 1820-1226 but I don't have a spare. I have an HP-45 that has an 1820-1061. I'm wondering if that part is interchangeable with the one in the 65. Both are 20 pins and both use the same anode driver 1820-1829.
Can someone point me to the link to the (a) discussion of classic display repair?
Does anyone know if these two parts are interchangeable?
|Re: Cathode Driver Question for Classic Calcs|
Message #2 Posted by Erik Wahlin on 5 Mar 2001, 1:27 a.m.,
in response to message #1 by Mike
The article is Alex Knight's article at http://aknight.home.mindspring.com/clasdisp.htm
I am pretty sure that the chip from the 45 would work in your 65.
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