Pulsar Calculator, faulty Crystal ?

[andyz4000]

Told my wife I was looking at this and my dog sat on the "Buy it now Button"

Lucky cause it seems like a good deal, has anyone done an Xtal repair on this model?

http://cgi.ebay.com.au/ws/eBayISAPI.dll ... %3AIT&rd=1

[Lordpulsar]

Yeah, I've changed crystals on the calc before Andy.... Two things here : Getting the module out : The display is open to the elements and the wire bonds are totaly un-protected on the LED display... Be careful !!

The crystal can also be the Sapphire (laminated type)... usually these de-laminate when you apply heat to remove them..

Its a tricky one !! :wink:

[andyz4000]

:) Cool, thanks Simon, I was hoping I would get a reply to this post. I have never seen a calculator let alone worked on it.

Much appreciated

[Lordpulsar]

The module has 4 little screw hinges in each corner and (usually) a blob of Epoxy covering them.. When you clear the epoxy and back the screw off, the little metal swing arm's that hold the module in, can be moved out of the way.. You probably will still have to pry the module out... But, be real careful.... The flexing of the module can break the wire bonds ! Its very delicate ! 8)

[andyz4000]

I,m hoping its only the crystal but there is always a chance the problem could be further in the circuit, the fact that all leds light and the calculater part works gives me some hope. I should be ok if its a wire bond but its just extra work so fingers crossed. It would be great to add a working Pular Calculater to my collection so I will be extra carefull and if you dont mind I will give you a shout if I get stuck :wink:

[Lordpulsar]

Best not to sink a few beers before you tackle it , Ay !

Have fun ! :D



Oh, forgot to mention....... These are the correct boxes for it ( bit pricey though)

http://cgi.ebay.com/Pulsar-time-LED-com ... dZViewItem

[andyz4000]

Simon, it arrived today and I fitted a new crystal (I actually had the exact same type). It works perfectly now.

This is the newer version Calculator with flick and very very mint so I'm pretty happy to have a win for a change. BTW the Crystal was at the rear next to the batteries so I did not have to pull it all apart and it was only a 5 minute fix.

Thanks again for your help :)

Andrew

[Lordpulsar]

Hi Andy

You are more than welcome and I am glad it all worked out for you.

S.

[retroleds]

[Note: This posting was made at same time Andy announced his success...consider it only for your edification if you haven't worked on a Calc. before]
Andy - Simon is right, proceed with utmost caution, particularly taking the module out. DO NOT GET CURIOUS(yelling for effect, only) about the layers of the module....there is a thin plastic substrate that keeps the buttons from contacting the module board - you move that, you are shot. And yes,the wire bonds are TOTALLY open - don't get curious on a potential/part worker.

And now the actual buttons: DO NOT TURN THE WATCH CASE OVER!!! Sure, there is a rubber membrane to keep the buttons up off the module and to seal it from moisure, but over time they get loose and floppy. IF you turn the case over, you may be faced with either trying to turn the buttons back to their correct position with a needle(this can be done), or removing the membrane to do it from the back side - no fun either way. IF you are worried you might do something crazy like knock it off your workbench, I suggest you cram a piece of foam into the cavity and snap a rubber band around the case to hold THAT in, before getting into the module.

Good luck...let us know how it goes.

I am so glad to get back to something constructive here.

[andyz4000]

Yes well I'm all out of words untill I see more of it then I will be back on my soap box.

Reminds me of that cartoon with the sheepdog and the wolf, clocking of at the end of the day. "bye Burt, See ya tomorrow Ralf"

Anyways back to the subject :wink:

Still gratefull for the tips guys, the Pulsar Calculator is a lot smaller on the wrist than I thought, this one is too minty to wear so I will look for an every day wearer which may need work.

I took a couple of pics of it working at all stages (of course the Calc works but that was a given.

[retroleds]

Very nice Andy. Your's is a second+ year model...the first year models had the buttons in a slightly different pattern, notably the "c" and the "=" were reversed.

[Lordpulsar]

Andy

Is this the one you got on EBay for $250 Buy Now ?

[andyz4000]

:) Yes, I just happend to see it newly listed. I figured for that price I would have a shot at repairing it.

[azimuth_pl]

A few days too late, as these pictures could have helped you:


More pics on my website. Enjoy.

[andyz4000]

:wink: Yes I checked your web site az, you have a lot of great information so I check it often.

[azimuth_pl]

Nice to hear Andy that somebody is watching my site :), thanx

[CompuChron2]

Yes I confirm as it seems to please you , that your site , Azimuth, is great and not only for LED watches.
I often browse it to look for a piece of information and I stay there for hours.
Thanks for this great job!!
P.S: Do you confirm that a BULOVA driver N7 (6 digits) with the same segment missing on all the digits is not fixable?

[azimuth_pl]

Hi there,
your words are greatly appreciated. it took me 6 months of constant work to get it created and I even added a comment-board to get any opinions of improving my website but there weren't comments so I removed the guest-book as it seemed that my work was not needed by anybody. that's why I'm very glad that my big effort of sharing this knowledge helps people.

in reference to the N7 drivers Bulova, the same missing segment, needs exposing of the chip and only the models with plastic cover can be repaired. so it is repairable but requires a steady hand and a good silver epoxy.