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My HP45 appears to have a strange quirk.
For the first 3 minutes or so after I turn it on the y^x key does not work. All other keys are OK. After that it seems to be ok.
I think I read somewhere that some HPs need a bit of time to warm up. I wonder if this is what is happening.
Has anybody else come across this strange phenomena.

I have never experienced or heard of any such "warming up" phenomenon. More likely the y^x key contacts are dirty. They are relatively easy to get to and clean. Post a reply if you care to try to clean them and need instructions, or search the Forum archives.

Howard:

>I think I read somewhere that some HPs need a bit of time to warm up.

Mmm... solid-state electronic devices need no warm-up time; they start working the moment you power them up. However, as Jeff mentioned, your HP-45 may have a dirty contact under the [y^x] key.

-Ernie

I've never hear of this problem on the 45, but some 21, 22 and 25 do have a warm-up issue. Although solid-state devices don't normally need any warm up time, when the chips are marginal heat can make a difference in their performance (both making things work and not work).

The 3 Woodstocks mentioned sometimes develop a problem with their memory chip where it will not work a until the chip heats up a bit. If you let the calculator stay on for a few minutes then turn them off and back on this usually fixes the problem. You can bypass the warm-up time by heating the chip slightly. I also have seen 65's that work fine until the CPU chip has been on for about 5 minutes. If you cool it off it start working again.

That said, I suppose that the 45 in question could have a marginal ROM chip and heat makes a difference.