Pulsar 3013 segment problem

[Chris S.]

Its been a while since I posted on here but I have been reading and learning from the many posts by the members so thanks for that.

Anyway I recently bought a Pulsar (not sure of the model but the module is the 3013) with a missing top segment. The transistor was missing for the this segment so I inserted a transistor (like for like) from a spare module and the bad segment came to life Problem is that this segment is consistently brighter than all the other segments

I decided to change all the other segment driver transistors from the donor module in case there was a difference with the transistor type but the results were the same.

What I have noticed though is when the individual segments display a "1" or a "7" the brightness is uniform (at the brighter level) but all other numbers show the top segment brighter.

It's got me stumped so if anyone can throw any light on the problem (no pun intended) I would be very grateful.

[bruce wegmann]

Can you post a couple pics of the display in these conditions? That would go a long way toward helping me get a clear image of what's going on here... I've seen one or two cases where the restored segment was dimmer than the others, but never brighter; there's something else going on here...[/url][/u]

[Chris S.]

Hi Bruce. Thanks for the interest. I've just spent the last half hour trying to take a picture which shows the problem. It's easy to see with the eye but difficult to photograph.
The images I've taken aren't good enough so I'll give it a go in the morning (its getting late here and I'm knackered) with a proper stand for the camera to stop shake and try to get the exposure right.

[Chris S.]

Hi Bruce. OK sorry it took so long. I eventually had to dig out my Canon EOS 400D (had several years and still don't now how to use it)!

Anyway I've hopefully attached two pics for you to look at which shows the problem clearly. Notice that the 7 has uniform brightness but the 3 show a brighter top bar.

Just a bit of history with the watch, when I got it (from the bay) the missing transistor had been replaced with a resistor which obviously didn't work so I though ah easy fix! Should have known better.





I should point out that the display is perfectly legible and the lower brightness digits would be fine as the standard brightness if all segments were the same. I used an exposure to amplify the difference in brightness only.