Open up HP12cp?


Is it possible, okay to open up HP12cp? My understanding is the procedure to do it on regular 12c is to remove battery door / battery and rubber strips on feet then 5 screws. I have an HP12cp that appears to have some "artifact" or debris between the clear cover on case and actual LCD. In doing some research, I found that one calc repair place would not work on the HP12cp stating they were not designed to be opened up. Had anyone opened one up? Does it cause any irrepairable damage? Pictures? Any thoughts are appreciated. I would like to try and open it up to see if I can remove that artifact in there. And in case you are questioning it, it does appear to be some little bit in there and not a problem with LCD itself. Thanks for any information you can provide!



removing these debits will be realy hard because, althrough you can open the 12C, you can not detach the PCB from the top case without causing hard to fix damages...

maybe it's time to get one of these new super fast 12C :-)

However, if what you have IS a new super fast 12C, then you should be able to open and clean the issue as the PCB has changed.

regards, cyrille


Yes, for clarification I do have the new Platinum version. I was disappointed that a blemish like that would get past HP QC, which I guess no longer exists. Too bad.


Mike, the new platinum version is not the same as the new super-fast 12c Cyrille is talking about. If yours is the platinum, it is not the new ARM-based 12c, what is being called the 12c+ now.


Well, to be fair, HP is no longer producing these in Corvallis, and the unit price is about what, say 33% of what it was when originally issued, in real dollars?

That is not to say that there shouldn't be QC. But it isn't the same thing is it?

Really, with these sorts of very low-cost technical devices, there isn't enough money to do "QC" the old way. Rather it has to be SPC/SQC of the manufacturing system. This means that some finite number of flawed devices will come through the line ,undetected--and that you them minimize the total cost by accepting some finite number of warranty trades for less expensive processing....and by statistically tracking the warranty issues, you then improve the process to reduce the statistically significant flaws.

Lots of gobbledygook but the fact is that any significant handwork is out of the question....

Edited: 31 July 2009, 12:17 p.m.



As a mater of fact, they are QC, and if indeed there is dirt in the screen, it should not have passed QC...

can you send a picture?

regards, cyrille


If the dirt has crept in after manufacture (from you pockets?) it should be possible to blow it out with some canned air.


My 12c (latest pre-ARM version) that I bought last year also has a few specks of dust under the display cover (had them since day 1 when they emerged after a few hours of use). They are pretty annoying.

I tried canned air, but it did not dislodge any of them (nor did it introduce new ones). I suppose that there aren't any significant gaps between the display and the case.


Edited: 1 Aug 2009, 6:18 a.m.


Well, to be fair, HP is no longer producing these in Corvallis, and the unit price is about what, say 33% of what it was when originally issued, in real dollars?

This made me curious, so I just looked up the original MSRP ($150 in 1981) in the CPI Inflation Calculator. In today's dollars, the original 12C would cost US $355.93. The new 12C is available today for US $66.00 at some retailers, so it's really only 19% of its original cost, and many times faster! That's quite something if you think about it.

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