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A non destructive (easy) method for opening a spice calculator.

Posted by Geoff Quickfall on 27 May 2009, 1:47 p.m.

Hello again,

To start, I hesitated to repair and restore my spice units until I read or developed a technique to separate the two calculator shells. I have seen described a pull apart method with a lot of force used and deformation to the polycarbonate case. Hence the following posting.

I have used this method succesfully on 5 out of 5 spices. It did take one almost destroyed unit to figure this out. Actually the unit came in a total mess and the only salvageable stuff was the LED panel (solderless), battery hatch and battery hatch ribbon.

Obviously HP had an easy way to get into a spice, apart from the pry and pull and push method that makes one very reticent to work on one of these.

After careful examination of the case I have created the following steps to get in.

Of course, the obvious, looking at the back of the calculator or bottom shell we see the battery hatch. Unlike other HP's there are no hidden screws (figure 1).


Remove the hatch and you will see two screws (figure 2), remove these.


Once the screws are removed, grasp the calcuator and lift apart the two halves at the battery end (figure 3). The calculator will pivot around the foot of the two shells. Only pull the calculator apart as far as the figure indicates.


Now that the two parts are separated at the top of the calculator, insert a long and extremely thin knife blade into the seam which separates the shells at the foot of the calculator (figure 4). The seam is vertical to the longitudinal plane of the calculator. That is, the bottom shell fits inside a lip of the top shell. The knife must be inserted vertically for a very shallow depth (1mm) and then turned horizontally. This has the affect of lifting the bottom shell out of the upper shell lip at the foot of the calculator. You will see why this is important soon.


Now that the bottom shell is above the lip of the top shell and while keeping the knife in place to keep the bottom shell out of the top shell recess, give the calculator shells a twist (figure 5). This is a horizontal twist; each shell in the opposite direction of the other. Be gentle as this method does not require force.


In figure 6 we can see that the bottom shell now protrudes past the top shell. Refering to figure 5 again, and while still applying a twisting moment as described, give the knife a gentle twist. This will pry apart the bottom shell and top shell. This combined with the twisting moment you are applying to the case will release the internal latch mechanism. The mechanism will release with a quiet snap.


In figure 7 you can see the L shaped latch which causes the headache, well, maybe not any more! Arrow 1 shows the direction of the twisting moment applies on the latch with the knife in place and the bottom shell raised out of the lip. Arrow two shows the final twisting moment of the kife releasing the two halves.


Of course it is difficult to describe but in summary:

1.  remove screws
2.  insert flat blade at foot of calculator to raise the bottom
    shell out of it's recess (lip) in the to shell
3.  while the blade is in place and the bottom shell is raised;
    give the two shell a rotational twist which will raise the
    rest of the bottom shell out of the recess
4.  give the knife a rotational twist while still applying the
    rotational twist to the two shells
5.  you should hear a gentle satisfying snap as the L shaped latch
    separates from its anchor point.

It's that easy!!

Cheers, Geoff May 2009


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