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HP-39GII: Will it become a desired collectible?
01-17-2015, 09:27 PM
Post: #43
RE: HP-39GII: Will it become a desired collectible?
(01-17-2015 12:59 AM)Hlib Wrote:  In parallel to the main power supply has arisen resistance value of approx. 300 ohm, which is continuously discharged elements. I removed some of the electrical circuit components. The functioning of the calculator is not affected, but the problem persists. Probably, a fault is in the STMP.
When the voltage on the elements 1.3 V, only a short pulse of 5 V through USB can turn it on. And when the battery indicator shows 1 charge bar, after "Power OFF" the 39gii continues to consume current around 50 mA and kills the battery.

Nice photos, thanks!
Sorry about your calculator fault.

I saw many situations where the current is well above the nominal value, and typically the problem can be related to faulty RAM or ROM memories.

Because the calculator can turn on, and assuming it can do normal calculations, I would replace the H27U1G8F2BTR NAND flash memory in first place.
However, I wouldn't recommend SMD devices replacements unless you have access to a professional workbench.

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RE: HP-39GII: Will it become a desired collectible? - jebem - 01-17-2015 09:27 PM

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