HP-33C dead after connecting Charger witout batteries



I guess I have killed my HP-33C. I made the mistake connecting it to the AC Charger (82090B) without a inserted battery pack.

Now it doesn't display anything. I have inserted a battery pack but it is still death.

Have I killed it?
Is there any hope in repairing it?

Any ideas welcome.



Edited: 8 Nov 2010, 10:27 a.m. after one or more responses were posted


According to what I've read in this forum in the past years, the majority of accumulator-driven CMOS calcs ("HP-xxC") die this way. Yes, I've done it too :( - once. AFAIK there's no way to resurrect such a victim except another HP-xxC of the same kind :( But ask Randy of FixThatCalc - he knows for sure.

Sorry, that's all. It doesn't really help, I know.


Yes you killed your HP-33C ... and what comes next is the HP Museum PoPo (new American slang for Police) show up at your door steps for an arrest. Budy ... you are in big trouble!



Edited: 8 Nov 2010, 7:40 a.m.


There's a possibility that the overvoltage has destroyed the power supply module (which is built from discrete parts and can be repaired), and not fried the ICs. Have you tried swapping the power module with one from another calculator?


Joel Setton


No I don't have another HP-33C to exchange parts with.
I may get one in a few days. But the previous owner told me this HP-33C doesn't power up too. It may be affected with the same problem.
Although the previous owner said he doesn't know why it doesn't react when it is powered on.

I know I shouldn't have done this extremely stupid mistake.



I have killed my share of HP-25's using AA alkaline batteries. So you are not alone!


BTW: I was in your beautiful city a month ago!!

Edited: 8 Nov 2010, 9:20 a.m.


So you say AA alkaline batteries are not suitable for a woodstock calculator?

You were visiting Vienna? Or a business trip?


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