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WP34s flash technical erase procedure
01-28-2015, 01:38 PM
Post: #5
RE: WP34s flash technical erase procedure
Never mind. :-} I finally understand whats happening. I have one of my calculators in that frustrating mode (following one erase cycle) where the machine appears dead. I have confirmed that the erase cycle, power-on, reset works; but no flash, yet, because MySamba can't negotiate with the stupid Prolific chip-set in my Dynex USB-Serial converter. Its a great null modem to me headless workstations, just can't use it to flash. rats. I'm still waiting on my FTDI converter to come by the mails. I get the infamous 'unable to connect' message; so I reset and unplugged everything.

I noticed something Jebem noted some days back, that even though the 'erased' machine appears dead its possible to check the voltage drop on the reset pin after a power-on. Even though the machine appears dead the voltage on J33 (reset) comes up to just less than Vcc (and stays there) until 'reset' is pressed; the voltage on pin J33 then drops to zero until the next power-on.

An inverter will power the unit, but I not think the forward + current has enough guts for the flash operation/ scrubbing that idea. I'll either go with a temp three volt power pack, or just wait until the LM117 gets here.

Lator gators... I'll be updating my PhotoJournal page later this morning when I get my pics processed.

Kind regards,
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RE: WP34s flash technical erase procedure - MarkHaysHarris777 - 01-28-2015 01:38 PM

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