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HP-71b does not turn on when using batteries
12-19-2016, 04:12 PM
Post: #4
RE: HP-71b does not turn on when using batteries
The 71b used to work with batteries. The battery operation was intermittent. I would move the batteries around a little bit and the 71b would power on and operate fine - until the batteries moved around. I got my DMM out and found that the battery terminals that have the spring-look were corroded and not providing enough contact space to the batteries. I replaced the spring-look terminals with better ones from a donor 71b. After this, I found that the batteries and terminals were providing the correct voltages after each battery (1.5VDC, 3.0 VDC, 4.5VDC, then 6.0 VDC - until I allowed the final '+' to connect to the final terminal - then the voltage went down to 4VDC or less). I am referencing the 71b service manual on the theory of operation and trouble-shooting process. I am thinking that I have a bad CR2, Schottky diode. The HP part number listed in the parts list is 1901-0999. Does any know what the commercial part number is for this diode? I will begin searching the internet in hopes of finding a suitable replacement part.
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RE: HP-71b does not turn on when using batteries - hpcalcuser83 - 12-19-2016 04:12 PM

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