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Adding a crystal to the wp34s - how? - Printable Version

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Adding a crystal to the wp34s - how? - Cristian Arezzini - 07-10-2011

I just received the components to add a crystal to the repurposed 30b (thanks Eric). I opened the calculator, and it's quite obvious where I should put the crystal; but I have no idea where to put the capacitors (there are many empty pads), and I couldn't find any info around. So... Where do the capacitors go? :)

Thanks,
Cristian


Re: Adding a crystal to the wp34s - how? - Paul Dale - 07-10-2011

They go immediately to either side of the crystal.

They are labelled C3 and C4 on the 20b's PCB.

- Pauli


Re: Adding a crystal to the wp34s - how? - Walter B - 07-10-2011

... and they are really small. Precision soldering :-/

Walter


Re: Adding a crystal to the wp34s - how? - Cristian Arezzini - 07-10-2011

OK, thanks! They really are smaller than I expected... I hope I won't damage anything!

Cristian


Re: Adding a crystal to the wp34s - how? - Etienne Victoria - 07-10-2011

For my 47 years old eyes, a magnifier was mandatory.

Also, no ristretto or Red Bull for 12 hours prior to the modification and you should be set.

Steroids necessary to open the 30B case.

I succeeded by pressing hard on the side with thumb and inserting a FINE PLASTIC spudge in the opening whilst keeping the central part flat with the palm.

And yes, you need 3 hands for this: my daughter helped on this one :-)

Etienne

Edited: Didn't notice that Cristian had already opened the case. Sorry


Edited: 10 July 2011, 11:35 a.m. after one or more responses were posted


Re: Adding a crystal to the wp34s - how? - Marcus von Cube, Germany - 07-10-2011

HP should have added the capacitors, at least. I don't think it adds to manufacturing costs in any sensible way.