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Discussion Starter #1 (Edited)
As many G757 owners have discovered, the Seiko G757 tends to lose contrast in the screen over the years until the screen becomes unreadable. You can find many G757s on ebay that have this problem, and they're typically much cheaper than a completely working one. I've seen many different suggestions for how to fix this problem, ranging from disassembling the watch and leaving the PCB in your oven for a half hour, to dropping it in a bath of various cleaning chemicals. After several unsuccessful attempts to restore my G757s, I have finally found a way that addresses the root problem with the G757.

I noticed that on all of mine, the contrast got progressively worse every fifteen seconds, whenever another quarter of the second display was filled. This problem wasn't present when the watch was left in dual time mode, or another mode where the second display wasn't filling completely.

On the G757's PCB, there is a row of four rectangular SMD capacitors labeled "Upconverter Condenser" on the G757 service manual/parts list. These wear out after a few decades and must be replaced.

These capacitors should be 170 or 180 nanofarads, but some of mine were as low as 130.

To repair the watch, you'll need four 180 nanofarad capacitors.


What you need:

Soldering Iron
Helping Hands (Stand with magnifying glass and alligator clips for holding what you solder)
Tweezers
4x 180 SMD nanofarad ceramic capacitors. Metric 2012 size are slightly smaller than the original, but they should fit.
Thin screwdriver or solder scraper for unscrewing the PCB from the case
Magnet for holding screws THIS IS IMPORTANT

Optional:
Solder wick. These capacitors are small enough that laying a wedge tipped soldering iron over the top was enough to desolder both ends, but a solder wick would have probably made it easier.


Repairing the watch is pretty simple. Start by opening the outer case and taking out the PCB + inner case assembly. There's a metal clip with four edges holding on the screen, the mirror, and the plastic spacer. This can be removed by prying open the four clips attached to the green case.

The LCD interfaces with the PCB through two rubber strips that are commonly referred to as "Zebra stripes." These can safely be detached from the screen and interchanged with each other. The zebra stripes do have an up side and a down side. If you take a close look at them, you should see one side that appears to have a few thicker lines between the normal lines. This is the side that should be touching the PCB when the watch is reassembled.

With the case and LCD removed, carefully unscrew the PCB from the green case. If there's any corrosion or battery residue on it, the PCB can be cleaned with rubbing alcohol and a Q-tip, or in a rubbing alcohol bath.

With the capacitor side up, place the PCB in your helping hands.

Desolder the four capacitors and replace them with the new ones.

Now, you can reassemble the watch and it should have its contrast completely restored. This should work for all models of the G757.


UPDATE:
When I first made this repair, I used old capacitors from different G757s. These failed after two months when I fell asleep on them and they overheated. I replaced them with brand new capacitors, which has significantly decreased the power consumption of the watch. Originally, it would burn through batteries in a bit over 3 weeks from brand new to low contrast. Two months later, I'm still on the first battery I used after replacing the capacitor, and there's no noticeable contrast loss or any other indication of a dying battery.
 

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Help with my G757?

I picked up a beautiful old Seiko G757 405a with a Sterling silver and turquoise band at a rummage sale. I did a cleaning and tried replacing battery. No luck. Anyone want to try the dead screen repair mentioned in the forums?

I'm currently on contract in NYC (through end of August) and brought the watch with me hoping to find a local tinkerer or expert. I live full time in Seattle though and would be willing to meet someone up there as well.

Anyone wanna help a brother out? (Paid to do it obviously:)

Thanks!
 

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Discussion Starter #5 (Edited)
Mind posting some pictures of the PCB? I'm on the east coast, so if you're willing to drive to Massachusetts or mail it to me, I could try fixing it. I wouldn't be able to get to it until the 16th or slightly later though.

Melt, I tried that with one of mine, and it didn't work. Usually dropping the PCB in the oven will fix bad solder joints, or temporarily fix electromigration, which wasn't the problem with mine.
 
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