A long WP-34S night


It's 3:30AM and I finally managed to successfully flash my first WP-34S!!!

Opening the machines was quite easy, soldering the caps less so. They don't look pretty at all but I hope they still work as they should. I went for "the works" and did the IR diode as well but then found that I had used too short a cable to actually close the calc. When I tried to remove the cable it took the R18 contact pad with it, so I used the shell for the second WP-34S and the board will be the "IR-less machine". (Any suggestions if there is a way to remedy this are welcome, of course.)

Flashing with Flashwp34 worked on neither Mac nor Windows but MySamba did it on the first attempt (with me being quite nervous about having a bricked machine....).

On the first machine the LCD dropped out of its frame and I did not realize this and tried to reassemble it with the screen slightly angled and its edge pressing against the frame instead of being within the frame. This caused where alarming black spots to appear on the display and it took me quite a few attempts at closing and re-opening before I found out the reason (I admit I'm not an engineer).

Now it seems the IR cables push the shell away from the board a bit and the pins of the flash cable don't seem to reach the board as RESET has no effect. I guess I'll have to open it again to see where to move the cables.

Any hints on the best routing to avoid pressure on the LCD. I seem to see very faint shadows on the LCD where the cable runs now (it's a 0,15mm2 cable, the thinnest I could find).

Sticker Time tomorrow but now good night!


Hmmmh. Please let me quote from p.5 of the manual:

There are three optional hardware modifications requiring some fine soldering, cutting, gluing, and drilling a little hole in the plastic case of your business calculator.
It is no sorcery for a young electronics engineer with a slow hand and good eyesight, but might come close to it for others (including me). So check Appendix H and decide whether you want to do that yourself. Else look for somebody else who is able to do it for you if you want it.


But for the self-chosen challenges life would be dull.....and but for trying we know the boundaries of our abilities ;-)

(or maybe rather the German: "wer den Schaden hat....." ;-)

And I DID leave out the USB board because I knew I wouldn't be able to get the cutout done nicely....


Your wire is too thick. Use the finest gauge wirewrap you can find, make sure that the wires don't cross each other and you should be good to route them anywhere behind the display. I used 28 AWG wire, outside diameter is 0.65mm. This is easy stuff to find, Radio Shack has 30 AWG wire, even better!

Edited: 14 Apr 2013, 1:02 p.m.


I used a flat cable from a 80-wire IDE cable, but I had to carve a groove in the foam that presses against the LCD display. A flex cable in the proper shape would be a nice option, but I think this would be a bit expensive.


Cutting grooves in the foam behind the LCD is what I did as well to get everything to go back together nicely. Of course mine refuses to flash, so maybe it wasn't the right method, but it looks good when reassembled.


I had problem trying to flash mine too:


I hope you get it working. The USB board is definitely worth installing.


Thanks Gerson. I agree that the USB board would be very much worth the effort. I tried following the steps in your link and I did remove some non-present drivers, but I still the "Unable to connect" error from MySamba. I assumed awhile ago that I had messed up the install and had given up on a version 3 calculator. I'm back to believing that is case again, until another suggestion comes along.




Please follow the procedure given in the printed manual (incl. the troubleshooting guide, if necessary. And mind the footnotes). It should work.


Edited: 17 Apr 2013, 1:17 a.m.


Thanks Gene,
I've had some success based on your response and an e-mail from Jeff Turner. I'll start a new thread to explain my current situation rather than continue to piggyback on this one.

Thanks again,


I rerouted the wire and it's better now. Flashing worked as long as I kept manual pressure on the plug. As the LCD kept slipping out of its frame when closing the calc, I wondered if it would hurt to fix it in place with a small strip of adhesive tape?

Stickers applied, ready for action! Thanks to all the contributors of this project!

If I should ever try another one, I'll be sure to use thinner wires, Gerson! I actually had planned to use some old very thin transformer winding but the isolating layer had baked together and kept peeling off when I unwound it. Conrad (our next equivalent to Radio Shack) did not seem to carry wire-wrap wire.

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