Seiko H239-500C

July 3, 2020

So here is my Seiko H239-500C from 1981. These are sometimes referred to as “Robot” watches and I can see why.  Classic early 80s design when Seiko and others were playing around with designs for these “ana-digi” watches.   I have a recent interest in these types of watches as you will see here in my LCD page!

This was quote a project though.  Complete dead watch with no hope of ever working again.  I was lucky and saw a donor come up in Italy for very little money. It was working but the screen was badly burnt and it also did not state if the analog part was working.

Once arrived I was pleasantly surprised to find all parts of the watch worked so set about swapping that screen.  This was quite a simple affair of disassembly of main components,board etc. with screen in place I rebuilt and for a while it would not work , only half the screen but after more cleaning with IPA alcohol it finally lit up in every segment.   Pleased by this I turned my attention to the analogue part.  This was now not running.  On close inspection of the train wheels and step rotor using my microscope I could see lots of old oil  and dirt.   Okay this what must be causing the fault!  stripped it all down and cleaned in my Ultrasonic and then painstakingly rebuilt.  The train wheels are the tiniest I have ever come across at only maybe 3-5mm in diameter.  they were a pain to get back in position under the bridge but I did eventually manage it.  Battery installed and nothing! again my hopes were dashed….  until I looked at the coil….  then saw under my microscope a very small dent which had broken one wire.  

To fix this I tried some conductive paint in the spot, applied under a scope and to a minimum.   an hour later the watch was working!!!   what is cool about the analogue part is that with one “click” of the crown it advances 1 minute to clicks in rapid succession the hand forwards one hour,  and vise versa if you wind backwards. 

After this I refinished all the case , repolished all the bright parts and applied a brushed finish to the flats.  installed a NOS crystal and it looked so nice!   I did the same to the bracelet and reapplied the brushed finish on the links and polished the centre links in the middle.  

Overall I am gobsmacked as to how this one turned out in the end! really is an eye catching watch that I have now successfully reborn. This one I think will always stay in my collection as I have become fond of it after all the work to get it to look like how it does now.

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