Pulsar calculator 901

[egomon]

Hi guys for a long time.

I wanted a pulsar calculator for a long time and then I spotted a suitable watch for me on ebay ( ok price and gold filled, it had to be gold filled) item: 321421070217 Before buying it I requested from the seller to see pictures from the inside or has she/he tried any batteries in. I got the picture and it was clean from inside so I pulled the trigger for buy it now. Shipping to Finland was on the expensive side but the seller send it really promptly to me (from US to Finland).
I opened up the package and did not have new batteries so I did took some batteries from my other watches ( yes I know you should not to that).....and nothing.

So I waited 24 hours with batteries but still nothing. Today I vent to the shop and bought new batteries and put them in and got two middle colons when I pushed the pulsar button. The colons staid lit for couple of seconds and then gone. So I pushed the button and all the time the same result. So I had hope that something in the watch was still operational.

As I know the quarts crystals from this era were really unreliable and I had some new ones in my workshop and it is really easy to swap old one to the new one in this watch so I did it. It took me 30 sec. to do it :)
I screwed watch back back on and pushed the pulsar button and "voilà" it worked I had time date and seconds. I was so happy. Tried the calculator activation button "0" and there was no reaction at first...but soon I got "0" but no reaction. I let the watch sit with batteries and after 2 or 3 minutes I tried the calculator function again and it started right up. All the segments work perfectly and are the same brightness. So I think the calculator needed few minutes to "worm up".

Now my only trouble is that I do not trust myself to get the module out of the watch case to refurbish the case to the best of it. It is really beat up.
I want to thank Pjotr from Poland for hes help and very detailed led watch homepage of hes and the advice that he gave to me.

Best regards

Egon

[bruce wegmann]

That was a lot of money to risk on a "maybe"...more than I probably ever would. There was a stainless, double-boxed 901 in almost-mint condition that I put a $520 "tracking" bid on, never expecting it to go for less than $1000-1200, and ended up winning it; don't know how or why that happened, but it was far less a risk, as it was shown to be in working condition.
As for your watch, I have looked at the auction pics, and you have a real challenge ahead of you. I don't like to work on goldfill, and rarely do, because, to get a good result, the case has to be in well-above-average condition to start with, and this specimen has some serious condition issues. 80 microns sounds like a lot of gold, but it is only .08mm, or .0032 inch, thick, when new. All you'll be able to do, without going into the base metal, is take out hairlines and the lightest scratches, and lighten up the deeper ones, but a fully pristine appearance is not achievable here. You're going to need a new piece of glass, too, but that's a relatively minor problem. My experience has been that, in general, really full restorations are possible only on stainless and solid gold (and, of course, once done, never go on a wrist again). On the other hand, if this is going to be a "wearer", you should be able to get a very acceptable appearance.

[egomon]

Hi Bruce and thank you for your answer. I have had a lot of experience with restoring gold filled P3 exterior and with very good results so I think when and if I trust my self to open up this watch doe to exposed vire-bonds (take the module out form the case) the task to restoring this watch (metal sanding and polishing) will be a straight forward job. Actually I have a lot of questions for you as you are the Pulsar expert- how to you take the screen of from the watch? As one can not heat it doe to red film between the two clear class sheets? The glass is glued to the screen module what must come off if you what to change the screen! What type of color was used to color the numbers of the calculator? I think the correct way to apply the color is to color the whole button and then sand off the excess color to get good result?

Best regards

Egon

[bucko170]

With a little TLC I am sure you will have the watch looking superb again, don't forget the before and after pic's.

Less than £150 for a working Pulsar Calc' - that has to be a bargain! Congratulations on an excellent find!

[Phasar66]

I had removed the module from a calculator before and wire bonds on the display are exposed that's why is always advise to never ever rest the module
face down. removing is not hard and is kind of self explanatory after You remove the case back but You have to be careful, clean hands avoid static electricity at all cost and take Your time, You need to removed the silicon with small tweezers holding in place the four tiny oval washers, no need to remove the screws or washer completely, just loosen them to fold them back to free the module. Some calculators came with regular mineral glass time screens and where no laminated, but if Yours is laminated try heating just the case to remove the screen still attached to the frame and do not apply heat directly to the screen with a heat gun go easy it might no need too much heat. The buttons are tricky because they are easy to round when refinishing, they are 1/8 of an inch in diameter so You can built a jig to hold them, Bruce is right GF is not forgiven.
Good luck

[egomon]

Thank you Phasar for the info!

I have couple of questions for the pulsar experts:

- so the calculator 9901 module is not screwed to the case at all instead it is "glued" in place with silicon?
-from where is the best to get the grip from the module to take it out from the case?
-I noted that on my watch 901 there is color difference on the top of the watch from the bottom. Is this normal? The bottom is little bit more red colored gold then the top is.
-what color to you use to re-color the numbers of the watch face? I think the process is to color whole button and then just sand of the rest on top and color stays in the grooves but I do not know what color to use.

Best regards

E.

[Phasar66]

I'm not an expert but I will answer from experience. The module in not screwed to the case is held by four retainers on the inside of the case held by 4 screws that go only to the module and the silicon is either use for holding the retainers fix in place after securing and or discouraging removing the module off the case. You need to remove all traces of silicon loosen the screws and fold back the retainers toward the module to get it free, after that it comes out easy, use appropriate tools for this.
The buttons can be painted with enamel paint, i will try to avoid sanding on the gold filled and just wipe off the wet paint and see what happens maybe that will do it, if sanding is necessary go easy after the paint cures completely, don't rush things. The color shade is just oxidation from fingertips and sweat and will come of with little refinishing. good luck, take your time and put that module on safe place. a picture is worth 10000 words here are some.

[egomon]

Thank you Phasar for very helpful information and yes picture are more then 1000 words :)!!!

I will gather some strength )read: (courage) before I opened it up, but if I do then I will document every step (photograph)for future references and help others to repair there pulsar calculators.

Best regards

E.