Cleaning up a C153-5007

[dapellegrini]

I finally found some time to take my second C153 apart for a gentle cleaning and crystal replacement.  This one is from Dec 1977 (I was two months old).

The case is in two parts, and this is my solution for opening up using my cheap crystal press (some of you are going to cringe!):





And press, until this happens



The die is in contact with the crystal only (plastic and being replaced) so didn't bother to add protection.  

Once the case is apart, a fingernail or toothpick will separate the face from the module/keyboard gasket.





Then a little more work and the metal front plate/face pops off the crystal.  The crystal also holds the keys on this watch.  New crystal on left, old on right.  You have to transfer the keys, one at a time











You pop the crown out like you would any other watch.  Then the gasket comes off:



Which leaves you with this:





This just needed some light clean up around the edges and pushers...



If you don't want to get creative with the crystal press, there is a pry spot on the edge that is intended to all you to open this up with a more traditional case back tool, here - but I have no idea how you actually get to it with the watch pressed together:



Once cleaned up, first thing is to put the plastic ring back in the case back, the module sits on this:





Then the gasket



Then the face plate over the crystal.  This holds the keys in while a final cleaning is done of the inside of the crystal



And you are left with this loose sandwich





Then its back on the press to get the two parts to pop back together





This time with some protection



And a few different die setups before I found one that got even enough pressure to pop it together 



And all done.  This is about the extent of my watch making skills

[dapellegrini]

Oh and the battery hatch was jammed so I left it in during disassembly. The previous owner tweaked it closed against a frayed old gasket and I didn’t want to risk anymore damage forcing it open. Once disassembled you can grab the hatch from both sides and twist. Much easier.

[dapellegrini]

Also a word of warning... The first C153 I received was very dirty and I set out cleaning it up with 91% alcohol and q-tips.  The black edging is applied to the underside of the crystal - and alcohol will remove it!  Thankfully I was able to source replacement crystals - but be careful if your intent is to keep yours:

[dapellegrini]

Ok - here's the corner / edge where I think you are suppose to pry it apart.  Very narrow and at least a fair chance you will mark up the case a bit in the process:

[inboost]

Excellent write up dapellegrini! I had no idea the keys were individual like that, what a exciting moment that must of been when those spilled out for the first time

Makes my Casio CFX-200 look like a cheap toy compared to the build on this C153-5007. The Casio's keys are little metal shells bonded to a rubber membrane (much like your black gasket / keypad membrane) that has a rubber peg standing up for each key point. It's interesting to see how different companies attack the same problem.

And I had a similar heartbreak with my crystal too. It has a water applied decal with all the symbols of the advanced match functions and constants on the inside. In trying to clean the inside glass with IPA I damaged and lifted a piece of it. Took forever for a replacement to come from India that was rougher on the outside than mine but had a clean legend.

Nicely done!

Inboost

[hamburgers]

Apr 9, 2022 11:19:18 GMT -8 dapellegrini said:

You pop the crown out like you would any other watch.

Hello dapellegrini . I was wondering if you could describe how you managed to pop the crown out. I have followed the instructions in the Seiko manual: I depressed the plastic point just above the crown, and in simultaneously tried clicking out the crown, which didn't work.

I removed the LCD display to see if I could work out the mechanism, but it didn't really reveal anything. Any advice would be gratefully received.

[dapellegrini]

I would have to dig one of mine out, but from memory, it has nothing to do with the white piece of plastic there.  I think it is like many other crowns of the day - pull the crown out and you should see a little tab show up on the inside of the case, and the plastic should be cut away there so you can put a small toothpick or the like on that part - press it down gently while pulling the crown and it should come out...  It should not take a lot of force.  You are looking for a tab kinda like this drawing:




If you fix your eyes on that little margin between the plastic module and the metal case - where there is a cut out - then pull the crown in and out, you should see the tab come and go - disappear when you push the crown in, and pops back out when you pull the crown out...  There is probably even a little dimple in it, where your tweezer tip should rest when applying light pressure.  

Or I am completely misremembering it, and will have to pull one out to have a look

[hamburgers]

dapellegrini, you are an absolute star!!!!!!!!!!!!!!!!!!!!!!!!! Your instructions were so clear

I inserted the pick into the micro-orifice between the plastic and case; I could feel a spring like mechanism, which I pushed down as I withdrew the stem. It came out no problem! 

First major obstacle down! I am sure many to go. Again, thank you so much! I was so close to giving up.

Have a great weekend.

Burgers

[dapellegrini]

Glad that worked for you and good luck with the rest of the project!