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HP 37E - Battery charging issue
11-13-2017, 02:57 AM
Post: #4
RE: HP 37E - Battery charging issue
I did check the "simple" things that were suggested. The test results are very confusing. The charger output is 10.73 VAC. The 37E requires approximately 2.5VDC. When I insert the charger with no battery pack installed, with my multimeter connected to the battery pack leads, I read 2.35VAC, and 0 VDC. The calculator will NOT power on when only the charger is plugged in (no battery pack installed), and the LCD display flickers violently. Should the calculator power on with only the charger connected (no battery pack installed)?

When the 37E is running on the battery pack, inserting the charger causes one of two things to happen: either NOTHING happens, or the calculator's display goes dead.

If I jiggle the charger leads while the charger is connected to the 37E, then I do see voltage fluctuations on my multimeter. I am pretty sure the problem is either a flaky connection where the charger plugs in, or a bad component.

The good news is that the calculator runs fine on alkaline batteries (with tin foil connecting the two leads). I would prefer to restore it to its original working status. Anyone have a fully working 37E for sale??!! Now that I have 37E "fever", I would really like to give my son one that he can depend on. This one seems to be very flaky.

Thanks... John in Dallas
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RE: HP 37E - Battery charging issue - johnlyles - 11-13-2017 02:57 AM

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