Administrator
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For completeness, and discussion, I will include the picture of the PM1208M main circuit board as shown in the review video, part 1: A few notes: - This is the actual circuit board from my watch.
- It is interesting to note that the Quartz Watch (Mechanical hands) is powered by a buck supply on the main board. There is a battery compartment in the Quartz watch, but it is empty. A spring (similar to the ones shown, but on the other side of the board) makes contact with the battery terminal at the bottom of the quartz watch battery compartment. The small metal piece that would secure the quartz watch battery in place in the quartz watch is present, but it is secured out of the way. Ground is provided by another contact. This is different than on the PM1208, which requires 2 batteries.
- The spring contacts shown on this side (3) are (staring from the lower right, and going counter clockwise): Battery connection, Case ground, and Alarm (Piezo) drive.
- In addition to the spring contact on the opposite side of the board that connects to the quartz watch, there are two springs that connect to the electroluminescent backlight. There are also those rubberized contacts that connect the main board to the LCD display. These can be easily broken, and often very finicky in other devices, but fortunately in this watch, I had no problem re-assembling them, and all display segments work correctly.
- When I received my watch, the EL backlight did not work. I realized that the two springs were missing. I made some tiny coiled contacts from copper wire, and inserted them into the appropriate holes on the back of the LCD display. While my EL backlight is very dim, it does work, and is adequate to see the display in total darkness. It is my suspicion that they were intentionally not there. They were either not included at the request of the company (or government entity -- perhaps ROSATOM) that purchased PM1208M's, or they were removed later. I suspect this was done to reduce battery replacement from employees operating the backlight too frequently.
I often think about the person my watch was originally issued to, where he worked, what readings it would have indicated, and his fate. Wherever you are -- whatever realm you find yourself in -- I will endeavor to take care of your watch. Happy and Safe Rad Hunting!
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