bad capacitors

[metulburr]

I always seem to get products with bad capacitors. I know that things are not made to be long lasting, maybe even are intentionally made to break by a certain point . But i always seem to find myself replacing caps on things. A couple years ago i had to replace a few caps in my monitor. A year ago in my TV, and just recently my PSU died. Opened it up to find a couple caps needing to be replaced.

Why do these manufacturers not put good quality caps in? Its always the caps that fail for me.

As a result, i ended up just buying a set of 1000 various caps because im sick of buying one at a time as they break and having to wait for shipment (thanks RadioShack for going out of business).

[DeaD_EyE]

The planned obsolescence is a side effect of capitalism.
You should buy every week a new computer, smartphone, car, everything...

The opposite of this is, that machines and electronic products never break
and in this case they are very expensive or the manufacturer goes bankrupt.
In Germany we had some manufacturers for machines, which went bankrupt,
because the machines never break. Some of them are still used in production.

I have seen machines, where they scratched away the swastika and there was the text written:
"Im Auftrag des Führers ...."

The manufacturing year was 1935 and they are still used for production of rails for trains.

[Larz60+]

The planned obsolescence is a side effect of capitalism.

Beats not being able to buy at all

Usually bad caps are electrolytic ones that are too small for the current in the circuit, so they pop.
They also depreciate over time, so older items like tube radios will almost always have bad electrolytic capacitors unless someone already replaced them.
Mylars and disc caps don't suffer in the same way.

[metulburr]

I seem to replace electrolytic capacitors with electrolytic capacitors because i dont see the point in putting more money into something i am unsure will work further or not. However replacing caps with cheap caps seems to have double the life so far of my electronics that would of otherwise been trashed long ago.

[Larz60+]

Keep in mind that electrolytic caps have polarity and others don't, so it's important that they be installed
in proper direction. I learned about them when I was about 5 and stuck one in the AC outlet burned my hand pretty good.

[millpond]

'Good' ELECTROLYTIC capacitors contain rare earths such as tantalum, a primary source of which is China, which were temporarily restricted a few years ago.

When replacing caps, make sure they come from a reputable manufacturer, and have the composition listed on the Material Data Sheets.

Old electrolytics can 'dry out', but usually if unpowere for a very long time, and if they are the 'wet' type usually used in high voltage apps.

Its also a good practice to place a 0.01 or larger ceramic cap across an electrolytic, since the ceramics are much better at high frequency spike suppression than electrolytics which are typically good mainly for filtering 50-60 cycles in power supplies.