Dear All,

I’ve seen this problem many times. I have three G757’s showing this problem in the analog area. This has nothing to do neither with displays nor with zebra contacts. The problem has something to do with cirquit boards. Any ideas? This matter drives me crazy…

I’m ready to set up a special prize for a person who will find a solution or at least will be able to find element(s) of the cirquit board responsible for those blanks.

Pushing the metallic frame helps but only in case of G757 4000/4020/5020 and never works with 4050/405a :(

Thanks in advance!

Welcome Robotov
Id love to help, but am also very frustrated with the G757. The pressing of the metal lcd surround does suggest not enough power getting through those segments. As you have tried everything else including tape on the front of the lcd to increase the pressure on the zebra strip my only last idea would be a miniscule amount of wd40 on the contact on the board. Just try one you know isnt working to start with and see whether it makes any difference.
You can attach images to your posts here. Im still trying to fathom out how to include external images within the post.

regards

Adam

Thank you very much for the tip, Adam! WD40? It’s an interesting idea - I’ve never tried to use this spray for fixing weak contacts of faulty LCD watches’ cirquit boards.

Regards,

Ivan

I’ve made an idiotic test… The result is quite interesting. I got 4 G757 watches with the same problem (described above) and disassembled all of them. So, I had 4 cirquit boards, 16 zebra contacts, 4 displays, 4 metallic frames and all other stuff laying on my desk. I started doing a typical monkey job: assembling 4 watches from randomly selected spare parts. You know what was the result of my experiment? One of the newly created watches started working properly. So, there’s only one explanation ehich makes sense. This stupid “star effect” doesn’t really mean that you have a faulty cirquit board (zebra contacts, LCD screen or any other component). It looks like in some cases there’s a kind of incompatibility. Those different parts don’t like each other. Adam is right! Something is wrong with electrical contacts. Anyway, I’m going to analyze the result. Most probably, those ebay watches with the problem are “hand made” - some sellers simply put components together and think they can finally get fully working G757 watches.

What do you think?

Thank you for the Information, Seiko Kid! Your approach forked for me once, really. However, it was a G757 watch with 4000/4010/401b/5020 LCD Display type. Do you remember the model number of your fixed watch? I have another observation: the star effect mostly shows up in 4050/405a/4030 Series and it’s really difficult to solve the problem. The same effect in case of models with small analog area can be solved following your method in many cases. Infortunately, these versions of G757 experience a different problem (almost impossible to fix) - missing segments in the digital area. If you swap the screens of two types you might have “the star effect” for one screen and missing digital segments for another type of screen. That, actually, proves your theory regarding the zebra contacts.

Well, Seikos’ D138 use the same type of zebra contacts and it looks like this phenomenon doesn’t exist in case of D138. I’ve recently purchased a set of zebra’s; however, the replacement procedure shows no effect.

PS. This issue is not very critical in my case. Most of my watches are in a good condition. I’m just confused that I cannot find a reasonable answer to a question which seems to be very simple! We’re talking about 30 years old electronic watches! Usually, I feel comfortable enough with fixing modern electronic devices. OK, this has nothing to do with my job - this is just my hobby left from the early 1970s.

Hi Seiko Kid!

Thanks! Your answer supports my theory and observations.

Regards, ivan

Hello.  Interesting.  I don’t generally take watches apart; so you guys are way ahead.

But from reading the posts - it seems that the problem is caused by bad contacts.  I mean - if putting cardboard into the case for pressure is fixing - or changing out components from 5 watches of same type - causes one to work; then we are talking about bad contacts - and not faulty capacitor, resistor, circuit board, etc.

Anyone tried a quality Electrical Contact Cleaner??

Just wondering.

D.