HP 25 repair



#5

Hi there! Could someone help me?
I've got a HP25 which has not been used for a few years. The battery pack is now worthless. When I connect the machine -- via ac adapter -- to the mains the display's numbers flash quickly but the machine does not work. Is it possible to have it repaired? Does this happen simply because there are no batteries? What can I do?
Many thanks in advance!
Marcos


#6

NEVER connect a Woodstock (HP2x) or Spice (HP3xE, HP3xC), or an HP67, machine to the ac adapter without a known-good battery pack in place. You can damage chips. This is more likely in machines with continuous memory, but it can occur in any of them.

The HP25 will not work correctly without a good battery. It's worth rebuilding it to see what happens, though.

#7

Marcos,

Where are you ? If you are in Brazil, maybe me or other brazilian may help.

Renato

#8

If you have the original plastic battery pack holder you can easily convert it to use regular AA batteries by removing the little plastic "strip" which runs longitudinally along the holder and "secures" the rechargeable batteries. Without the strip in place, the holder is wide open, and it is a simple matter to insert and remove regular AA batteries (use the "stock" springs). Just remember to pay careful attention to polarity (I marked my holder with a "+" and "-" just so I won't screw up.

In a non-continuous memory machine this is a very simple and economical way to go, since you are not concerned with losing programs/settings when your batteries completely die.

Take care.

Wayne.

PS - To some, it is considered blasphemy to alter an original Woodstock battery holder, but I decided a while back that I'd rather have my HP 21 working than to have it useful as nothing but a paperweight. I can go back to rechargeables if I choose, and I even saved the little plastic "strip".

PPS - Some also say that you should not use brand new AA batteries because they produce more than the "stock" rechargeable batteries' voltage. Others have told me it makes no difference. Just to be safe, I use my AAs in a flashlight or something for a little while before installing them in the HP 21.


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