Capacitor testing

[ScottDG]

Hi Can anyone tell me how or what equipment is needed to test a capacitor & is there a visible sign that a capacitor is faulty, i know that it stores a certain amount of electricity but other than that very little. i hate to see a thing get dumped if it can be fixed but i do understand that electronics can be very dangerous & i do know my own limitations but i just want to understand & Learn

 

[Harald Kapp]

Hi Can anyone tell me how or what equipment is needed to test a capacitor

A capacitor meter would be suitable. Some multimeters have a built-in capacitor tester.
For electrolytic capacitors an ESR tester is useful.

is there a visible sign that a capacitor is faulty,

Yes, if it is mechanically defect, e.g. broken or in the case of electrolytic capacitors if the endcap has bulged or, worse, broken and has leaked electrolytic fluid.
It is kind of a standard procedure to replace electrolytic capacitors in older electronic devices if they operate erratically or not at all.
Ceramic capacitors usually fail only if they are mechanically damaged, although there is always the possibility of an invisible internal short or open circuit.
Foil capacitors are rather robust, but mechanical damage also happens to them.

We may be able to help you in more detail if you provide more information on the type of device and defect you are working on.

 

[ScottDG]

The device in question with maybe a doggy capacitor is a small TV i have a some knowledge of electronics. The TV when switched on only flashes the standby light on & off continuously. After researching plus taking to people they have said its probably a capacitor that is at fault, thats why i asked the questions, i have contacted several repairers who say the same but want me to pay them just to have a look at to the tune of £35- 50 without even a repair. I have looked up the same value of capacitors which are a fraction of the price which is under £1 it costs more on postage the TV it self is not worth £50 but if it can be fixed i will hate things just going to the dump all because its old & as they say not worth it.

 

[(*steve*)]

It's generally easier to replace all potentially affected capacitors. Knowing which ones is why you pay someone

Post some photos of the power supply and we can identify them for you.