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hp-91 transistor substitution
09-22-2014, 06:36 PM
Post: #8
joseaem Offline
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 		Posts: 4
Joined: Sep 2014
RE: hp-91 transistor substitution
LOCATED THE PROBLEM!!!
Main item, display the minus sign...
Due a transistor shorcuted in U3 anode drivers, tomorrow I will replace with a 2n2222 transistor.
Second item, the transistor break: The calculator is functional, because is a secondary energy element, making resitance lower at power demand increasing.
All thanks to HP 97 service manual.

Thanks for your interest, Jebem, Paul And Cruff


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Messages In This Thread
hp-91 transistor substitution - joseaem - 09-20-2014, 05:10 PM
RE: hp-91 transistor substitution - jebem - 09-20-2014, 07:17 PM
RE: hp-91 transistor substitution - cruff - 09-21-2014, 11:32 PM
RE: hp-91 transistor substitution - joseaem - 09-22-2014 06:36 PM
RE: hp-91 transistor substitution - jebem - 09-22-2014, 07:51 PM



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