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Full Version: HP-34C Display Looks All Matrix-Like
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Greetings! I received an HP-34C to sell on eBay (from my father-in-law). It looks like it's in excellent condition _physically_ but, when I plug it in, the display is flashing all manner of numbers and sometimes I see "Error 0" or "Error 3" flash by quickly. It really does look like something out The Matrix with everything going by so rapidy. Is it DOA and not worth saving, or is there some key combination I should press, or is it a problem with the battery pack in the back of it perhaps? Suggestions welcome!

If you're seeing an Error <anything> it's not DOA. This message is produced by the CPU in response to various invalid operations, etc.. Since the calc display is intermittent I'd guess that the chips are nor making good contact with the circuit board inside the calc. Some versions of this calc have the CPU chip and the 3 RAM/ROM chips held in place against the circuit board with spring steel clips. You need to take the calculator apart and re- seat the chips, display, keyboard and circuit board itself -- they all go together in a sandwich-like structure.

There are many references as to how to do this on this site.

Here are some of them:


http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/articles.cgi?read=361

http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv013.cgi?read=38031


Edited: 23 Mar 2004, 10:54 p.m.