We've all heard the saying in the title, and it's no different in marine electronics.
A customer came in recently with a chart plotter from a popular brand. The usual "it's just dead" was followed by some hand-waving about local yacht experts offering what he considered to be a high repair price for the generation of the plotter. Of course the plotter is connected to radar and instruments etc, so cost of upgrading is even more scary.
Turns out the yacht experts suggested a repair of around £650 after vat etc. In the light of having to maybe upgrade a system, this figure is actually not so high after all. It's probably just a fixed price repair as offered by the manufacturers, confirmed by the fact that the experts couldn't say what was actually wrong with it (even though they could offer a repair price) - hence the customer bringing it in to us for a second opinion.
It's a fault we've seen before and, because we've done the work previously to locate said fault, we were able to repair the plotter for the price of one hour's labour and a 50p component.
Of course that's not to say all item failures are like this, and sometimes a circuit board swap-out is more economical than spending time tracing a fault only to find there's no components available, or there's cascade damage (one failed component takes out several others in line) making a board swap necessary anyway.
So this is where experience comes into play. We may well have spent considerable time on a similar machine before, and from this we usually know what we can (and can't) repair for less than replacement. To use the words of the wise Mr Caesar, "experience is the teacher of all things"...
Another delighted customer I'm pleased to say.