Deep Blue watches was founded in New York in 2007 and quickly became known for their robust dive watches. Their range of watches includes a good variety of models with various dial and lume colours. This watch was one of their top of the range models when it was produced – a divers automatic chronograph. As it says on the dial, it’s a “Master Chrono 7750” – indicative of the ETA 7750 movement powering this watch. Versions of these movements are found in many quality Swiss chronographs, like those produced by TAG Heuer, Breitling and Omega, though it should be noted these brands customise the movement, often utilising high grade versions with enhanced accuracy.
Servicing the Deep Blue Master Chrono 7750 Movement
We begin by checking the functions of the watch – including the winding up, hand setting, date change and chronograph. Everything appeared to be in reasonable working order, though the watch was not performing well on our Timegrapher, so it was highly likely this would be a maintenance service without the need for any major repairs. It’s important to ensure your watch is serviced every 3-5 years, this will ensure it continues to function as it should. Even old watches can be restored by our expert watchmakers; learn more about our vintage watch repair service.
The ETA 7750 is an integrated chronograph movement. This means the chronograph mechanism is built into the “base” movement. This is in contrast to modular chronographs where the chronograph module is bolted onto a base movement, such as with chronograph versions of the ETA 2892A2.
The base of the 7750 houses the essential timekeeping functions, including the mainspring barrel, gear train, escapement, and balance wheel. This serves as the foundation upon which the chronograph complication is built. When we assemble a 7750, this section goes together first. That’s why it’s important to make sure everything is perfect and running well, as soon it will be buried underneath a chronograph mechanism.
Disassembling this watch is rather involved, as we need to check many of the 250+ components to ensure they are in good condition. We note a worn reverser – not unusual as this is a key part involved in the automatic winding mechanism. Otherwise everything is in re-usable condition, though we will replace the mainspring as standard to ensure we have a reliable source of power for many years to come.
Cleaning, Reassembly, and Replacing the Hands
With the movement fully disassembled and checked, it is cleaned – going through a cycle in our Elma Solvex RM automatic cleaning machine. Once parts are completely clean and dried, we can commence reassembly of the movement. During reassembly, we followed our typical servicing procedure using the manufacturer’s technical guidelines in terms of oil and grease usage, as well as the use of other treatments such as epilame.
Once we get to the stage of refitting the dial and hands, we fit a replacement set of hands supplied by our client. When handling watch hands we tend to use carbon fibre tweezers as when combined with due care this significantly reduces the risk of marking them.
With all works completed, we can case this Deep Blue Precision Divers Chronograph before testing it for water resistance. It then moves on test to ensure good timekeeping within tolerance, appropriate power reserve, and correct functioning. Once testing is complete, it is released ready for collection by our client. If you’re interested in the process of watch repairs, or you have any questions about servicing your watch, contact us using our Ask the Watchmaker form.
If your timepiece needs servicing or restoration, contact us today or visit us in store to discuss how our expert team can bring your watch back to its best.
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