Great Source of A1200 / A600 caps and other retro items

[mechy]

I'm asking question. If you have answer, please provide.

From this what I know, capacitors age only when USED.

No, all Amiga caps in all Amiga motherboards have well exceeded their life ratings.
Even if they are not leaking,they most likely have a reduced capacitance and/or may be completely bad.
These bad caps may not be filtering power coming in properly,or may allow noise or reduced volume on the audio etc.Dirty power can lead to random crashes and such.

Caps age mostly when not used.

 It is why the military cycle their electronics often,to keep the caps viable, otherwise they go bad quicker.

Its a bit like letting a car battery set dead,if you leave it that way long enough it sulphates and/or shorts the plates and usually can't be revived.

old caps can leak and the leakage can eat traces just like the leaking batteries. I have repaired many boards in the last 15 years with neglected caps.

Its like having 4 bald tires on your car, and one blows out.. you don't put 1 new tire on knowing the other 3 are about to fail...well maybe you do,but most people dont lol

[mechy]

I was thinking about capacitance decreasing in time. This is most convincing for me.

There is multiple types of caps... so called "solid" caps. Can I replace Amiga caps with any type (same specs)?

I would think that it should be fine? Why not to put there something what will last "for ever"? Since there are caps with no degradation?

Polymer caps(panasonic and other quality brands) are fine to use as replacements for electrolytics if the specs are matched, sometimes it is hard to find the value or size that matches however.

unfortunately there is no forever cap that i know of, but quality caps last between 10-30 years, look how long the originals made it and they were mediocre quality

tantalum,ceramics,foil,polyester,electrolytics all degrade eventually and some are not acceptable replacements for electrolytics.

i tend to stick with the panasonic long life ones.

Also keep in mind if you overheat it when soldering it it can reduce its life quite a bit.

[mechy]

I personally do not replace Amiga or any vintage computer capacitors if not required. My practice is to every once in a while (perhaps annually) measure each capacitor level with a multimeter. If I should see signs of age, I will replace, otherwise I leave them be if they show sufficient life left.

The reason for the above is simply due to minimizing risk of damaging any components such as the motherboard, solder pads, etc due to applying heat via a soldering iron, hot air, etc.

I am not saying the above is the absolute right way to go about it, but only what I personally consider to be the right thing to do, when trying to best take care of 30 year old equipment while assessing all possible risks of damage.

You cant test a cap with a multimeter, it will not tell you anything useful. The only way to properly test a cap is with a ESR meter and you would have to desolder them to do that.

soldering/desoldering caps is a basic,standard procedure in electronics, there should be no reason to cause damage if you are doing it correctly.

[mechy]

A pic of the recapped board here.

Looks like its all set to go