VII · Watch faults and diagnosis

The watch that kept time yesterday now stops in the afternoon. A clean crystal develops a haze. The date changes over lunch. Each symptom calls for a different response. Start with what you can observe safely and record when the behaviour changed. That is more valuable to a watchmaker than a guess about which part has failed.

When to stop wearing the watch immediately

Treat droplets or persistent haze inside the crystal as possible moisture ingress. Take the watch off, dry only the outside with a soft cloth and seek a workshop promptly. Leave the crown in its normal position if it is already closed. Avoid winding, pressing pushers, opening or heating the watch. A watch can continue running with moisture inside.

A loose crown, cracked crystal or clasp that opens by itself also warrants taking the watch off. After a drop, note whether the hands rub, anything has come loose under the crystal or a new noise has appeared. Take it for assessment without trying to straighten the crown or force the hands.

The mechanical watch stops during the day

If it was stored, it may simply have exhausted its power reserve. Consult the manual and wind it as instructed if the model allows. Note when it starts and when it stops. One interruption after an uncertain charge tells you little. If it stops again after being properly wound, record whether it was on the wrist, set down, or in the same position each time.

An automatic that runs after manual winding but has poor reserve when worn may have received too little movement or may need its winding system checked. A repeated stop at the same indicated time may prompt a watchmaker to look for contact between the hands or resistance in the calendar. These observations guide an inspection. The movement still needs to be examined to establish the cause.

The rate changed from one day to the next

Compare the watch with a time reference and record the difference after a few hours and after a day. Mention any impact, exposure to a magnetic clasp or unusual temperature change. A mechanical watch can gain or lose time after becoming magnetised. Other problems may produce a similar symptom. A workshop can check for magnetism and measure the rate in several positions before recommending regulation or overhaul.

If the deviation grew gradually over months, take your wearing notes and service history. Regulation corrects the rate under test conditions. An overhaul can address wear or lubrication problems identified on inspection.

The calendar fails or the crown catches

If the date consistently changes at noon, check the 24-hour cycle first. The watch may be set 12 hours out. Read the instructions for the reference before using the quick-set. The period during which the calendar is engaged varies between calibres.

If the disc repeatedly stalls between numbers, the date stops advancing or the crown begins to catch, avoid forcing it. Note the indicated time and crown position. With a screw-down crown, use only the usual pressure when closing it. A thread that no longer engages may be damaged. Keep the watch out of water until it has been checked.

The quartz watch stops or its hand jumps

Some calibres signal low energy by jumping several seconds at a time. Check the behaviour specified for the model. For battery quartz, ask for replacement and a gasket check, especially if you intend to get the watch wet. With a solar watch, follow the charging guidance and tell the workshop if reserve remains poor after proper charging. A disposable battery and rechargeable cell are different components.

If a chronograph appears stopped, first check which hand displays running seconds. On many models the central hand moves only when the chronograph is running. If it no longer starts, stops or resets as it used to, avoid repeatedly pressing the pushers and describe which step failed.

What to ask for at diagnosis and collection

Provide the reference, symptom, when it began, when it repeats and the date of the last known service. Ask for an estimate that separates the work, parts, labour and final tests. If the case or dial has collector interest, record your preference about polishing and replacement of visible components in writing.

At collection, ask what was done and what was tested. Check the function that brought you to the workshop and keep the invoice with the watch history. It is easier to follow a repair when you can distinguish the initial observation, the cause found and the test result.