Well, my new set of jeweler’s screwdrivers arrived yesterday, so last night I performed some long overdue cleaning, exploratory surgery and battery replacement on this enigmatic Gruen.
Initially I found myself struggling with my magnifying glass in order to negotiate the tiny ~ 0.6mm lug screws securing the metallic band. Once out of the way, I tossed the band pins and all into a lined box and soaked it with a generous dose of WD-40 while contemplating its fate. Had it not been the original band with Gruen embossed clasp, my decision would be an easy one; just scrap it in favor of a fine calfskin or lizard strap that would look good and also be a bit more comfortable to wear for extended periods of time.
Cleaning up the module was quite effortless, as the circuit board traces, battery contacts and function input contacts are all gold plated, thus no corrosion. I actually carefully went over the module with a low power microscope in the hopes of finding a clue as to which company manufactured this early flick wrist model. My search turned up fruitless, though MADE IN USA is faintly embossed on the LCD panel side of the plastic carrier. Also, I noticed that the quartz crystal is packaged in a rectangular case. After the holidays, I plan on picking up a used frequency counter, and this will be the first module I test.
Upon cleaning up the case, I encountered a setback that cost me a night’s sleep. Consequently, as I write this, I’m operating on residual caffeine energy. Some of the cleaning alcohol that I applied to the Q-Tips seeped beneath the Plexiglass crystal -- causing the 39 year old glue to blacken and dissolve.
It’s a good thing that I stock lots of Q-Tips and isopropyl alcohol, as I went through quite a bit of these cleaning up the resulting mess and removing the remnants of antiquated polymer from the crystal and bezel. Once clean, I re-glued the crystal in place and had to allow it to set before applying some clear plastic protectant to the Plexiglass crystal, buffing with Q-Tips and assembling the watch.
I’m attending a major party in a couple of weeks, and while not the best looking LED watch in my growing collection by far, I plan to wear this particular watch because I think that the early dot display and mercury switch function will be a good way to introduce non LED heads to our hobby.
Happy Collecting!
Jason
‘70s LEDs until the end of time!