Searching for my brother's Casio LIN-164 that needed a battery change I've found another interesting item: my old and supposedly broken Casio Edifice EF-503 was scraping against some nasty Chinese knock-offs on the bottom of a grocery bag destined for a garbage bin. It was me who discarded this Casio some six years ago, profoundly disappointed in this brand because my beloved watch completely stopped working a couple of days after its first battery change - no-brainer work performed by a well known downtown Belgrade watchmaker. I returned my dead Casio back to the shop hoping it was just a a hiccup, some trivial electrical contact issue or other thing of a sort, but watchmaker kept the watch for seven days and still couldn't find the reason why sturdy and reliable Citizen-Miyota OS10 movement failed miserably after some 2 1/2 years of normal use... Casio's 2-year warranty had expired by then and price estimate for a movement swap was very close to price of a new watch, so I decided to take my ill-fated EF-503 home and dispose of it. Yet I didn't throw it in a garbage bin as I meant to do in my thorough disgust. Soon I bought a 2010 Seiko SNK803 "Desert pilot" automatic as a replacement, had some important changes in my life and consequently lost track of a crappy broken Casio, nevertheless a bitter taste in the mouth remained.
Having recently read this tutorial on DIY repair of quartz watches, I was hoping that something still could be done with my Casio, so I've removed the screw back using an old Richter compass instrument, taken out the expired battery, carefully scrubbed off the gunk around the gasket with a wooden peg (highly praised certified watchmaker didn't bother to do any cleaning prior to battery change), removed the stem/crown (has to be fully in before you can unlatch it, pressing a recessed tab), pryed out the white plastic retention ring (four prying points are clearly marked on the mov't back plate) and gently taken the movement out, blew some compressed air around and inside and then installed it again, inserted the stem until it clicked into normal (running) position, applied silicone grease on a clean gasket and finally finger-tightened the lid, as I planned to get a proper new battery tomorrow morning...
I also had luck with my bro's blue dial Casio LIN-164 that day: battery change and gasket cleanup/lubrication went OK, without any scuffs to its beautiful matt gray surface... This watch has an ultralight blast-finished Titanium alloy body and bracelet which is held in place by two split pins instead of spring bars. Its screw back was stuck like it had been welded, but it finally gave way.
Next morning I've bought one Renata 395 silver battery at the local market for EUR 1.40 and installed it without much hassle (you don't have to undo any screws on OS10, just gently pull on the elastic retainer lug with a flathead screwdriver and pop the batt in). Crown was in its 2nd position (fully out) so the movement couldn't start ticking yet. I've pressed the crown fully in (the moment of truth!) and my watch started running right away! Then I tightened the case back, did a chrono reset per factory instructions, set time and date and rejoiced... Chrono worked fine, although I needed factory instructions again to find out how to use the functions correctly. I guess the most probable cause of a dead quartz movement was a tiny particle that remained loose inside the movement after the "dirty" battery change and finally got stuck somewhere between the moving parts, stopping the very sensitive drivetrain. I guess I managed to blow it out using low pressure compressed gas from a can. I know that any pro watchmaker will cringe on mentioning of this "procedure", but I had nothing to lose and it solved the problem with little work. I have yet to check the long-term accuracy, although I don't think it was especially accurate back then while it was new (factory spec says ±20s/month is normal).
That same day I've buffed out one particularly annoying scuff on the mineral crystal (yes it's possible, but mind the heat!) and did some buffing on the stainless steel case, in both cases using Purol polishing paste and solid felt wheel on Dremel 300 rotary tool (in 3rd speed, pressing lightly, changing direction of passes). I suppose it was possible to achieve a mirror finish using chrome green but I decided to stick to a familiar compound even if it wasn't ideal for this purpose. I didn't bother to buff the case back, which is visible here:
Having recently read this tutorial on DIY repair of quartz watches, I was hoping that something still could be done with my Casio, so I've removed the screw back using an old Richter compass instrument, taken out the expired battery, carefully scrubbed off the gunk around the gasket with a wooden peg (highly praised certified watchmaker didn't bother to do any cleaning prior to battery change), removed the stem/crown (has to be fully in before you can unlatch it, pressing a recessed tab), pryed out the white plastic retention ring (four prying points are clearly marked on the mov't back plate) and gently taken the movement out, blew some compressed air around and inside and then installed it again, inserted the stem until it clicked into normal (running) position, applied silicone grease on a clean gasket and finally finger-tightened the lid, as I planned to get a proper new battery tomorrow morning...
I also had luck with my bro's blue dial Casio LIN-164 that day: battery change and gasket cleanup/lubrication went OK, without any scuffs to its beautiful matt gray surface... This watch has an ultralight blast-finished Titanium alloy body and bracelet which is held in place by two split pins instead of spring bars. Its screw back was stuck like it had been welded, but it finally gave way.
EF-503 on a flatbed scanner
Next morning I've bought one Renata 395 silver battery at the local market for EUR 1.40 and installed it without much hassle (you don't have to undo any screws on OS10, just gently pull on the elastic retainer lug with a flathead screwdriver and pop the batt in). Crown was in its 2nd position (fully out) so the movement couldn't start ticking yet. I've pressed the crown fully in (the moment of truth!) and my watch started running right away! Then I tightened the case back, did a chrono reset per factory instructions, set time and date and rejoiced... Chrono worked fine, although I needed factory instructions again to find out how to use the functions correctly. I guess the most probable cause of a dead quartz movement was a tiny particle that remained loose inside the movement after the "dirty" battery change and finally got stuck somewhere between the moving parts, stopping the very sensitive drivetrain. I guess I managed to blow it out using low pressure compressed gas from a can. I know that any pro watchmaker will cringe on mentioning of this "procedure", but I had nothing to lose and it solved the problem with little work. I have yet to check the long-term accuracy, although I don't think it was especially accurate back then while it was new (factory spec says ±20s/month is normal).
That same day I've buffed out one particularly annoying scuff on the mineral crystal (yes it's possible, but mind the heat!) and did some buffing on the stainless steel case, in both cases using Purol polishing paste and solid felt wheel on Dremel 300 rotary tool (in 3rd speed, pressing lightly, changing direction of passes). I suppose it was possible to achieve a mirror finish using chrome green but I decided to stick to a familiar compound even if it wasn't ideal for this purpose. I didn't bother to buff the case back, which is visible here:
This watch originally sported a black faux leather bracelet with white stitching (full model name is "EF-503L-1AV", module 2328). Rigid and uncomfortable OEM bracelet is long gone and new 20mm NATO gray nylon strap is already being shipped to my address. Oddly, this is my only watch that's completely silent: even my
thick-cased Q&Q KW68 "Submariner" (powered by an ultra-accurate sample of Miyota 2035 quartz) ticks audibly...
Wears a bit bigger on 18mm strap, also black goes well with almost all imaginable outfits. Shown here with vintage Yugoslav Air Force leather jacket.
Wears a bit bigger on 18mm strap, also black goes well with almost all imaginable outfits. Shown here with vintage Yugoslav Air Force leather jacket.
