Diagnosing a watch
Two halves. With a timing machine, almost every mechanical fault leaves a signature in the shape of the trace — and that shape tells you not just that something is wrong but usually which component. Without one, there is the problem catalogue: forty-two things a watch actually does — mechanical and quartz — what is happening inside when it does them, and what to do about it.
A timing machine plots one dot per beat, scrolling downwards. Everything you diagnose from is in the shape of those two columns of dots.
- Lean Rate error, in seconds a day. A straight but leaning trace is a watch that runs well at the wrong speed — a regulation job, not a repair.
- Separation Beat error, in milliseconds. Two parallel lines with a gap mean the tick and the tock are unevenly spaced.
- Scatter Noise. A fuzzy band instead of a line means friction is varying beat to beat — dirt, dryness, or damage.
- Shape Periodic faults. Waves and kicks repeat, and the period identifies the wheel.
The period tells you the wheel
This is the single most useful idea on the page. Time how often a disturbance repeats and you have narrowed the fault to one component. Figures are for 4 Hz (28,800 vph); scale them for other rates.
Trace patterns
Click any card for causes, checks and the remedy.
Nothing matches that.
Problem catalogue
Everything you diagnose without a timing machine — what the watch is doing, what is actually happening inside, and what to do about it. Each entry is tagged with how urgent it is and how far an owner should go before handing it over.
Nothing matches that.
Before you diagnose anything
Most bad readings are bad measurements. Rule these out first.
Target figures
What good looks like. Amplitude figures assume the correct lift angle is set — 52° covers most Rolex calibres.
Quartz: what to measure
Service intervals & lubrication
When things need doing, and roughly what goes where. Lubrication is calibre-specific and the technical guide is the authority — this is the shape of it, not a specification.
What goes where
Mistakes that cause faults
A good share of what arrives on a bench as a fault was introduced on a bench. These are the ones worth having in mind.