When the device does not switch on, the first things to check are the fuses. There are three fuses on the suction pump. There is one in the plug and the other two are in the fuse drawer, just below the power entry module.

If any of the three fuses are damaged, that will prevent the pump from operating. Usually the fuses are clear, so you should be able to see straight away if any of them have blown. Look and see if the wire inside is intact. If they are blackened like this one, it is a sure sign they have blown.

If in doubt, one way to check is simply to replace all three refuses and turn on the machine. If it does not, then clearly you need to keep checking where else the problem may lie.

To test the fuses with a multimeter, you simply do the test for continuity. When you have set the dial to continuity, you can touch the two prongs together to check it is working. On some models, you hear a continuous sound. Others will give you a reading.

The same thing should happen when you touch either end of the fuse. If it doesn’t, then it means the fuse is blown and needs replacing. Sometimes multimeters will give an OL signal when there is no continuity, or it’ll say ‘open’ or ‘not complete’.