The main failure point of all old electronics are the capacitors. Over time, electrolytic
capacitors dry out, and can cause a wide array of different faults. From ones that are
leaky, and or way out of spec, they can exhibit all sorts of ?fun? errors in hardware.
The main one i?ve come across is ?RIFA? brand rectangular thin-film filter capacitors.
These can be quite violent when they fail, and they fail often. Many power supplies can be
brought back (for a time) by just replacing these capacitors.
Electrolytics, whilst far more reliable (and less explosive) than the RIFA capacitors,
also dry out and go bad over time. However, uness your machine was built during the
?capacitor plague?, these can still be surprisingly reliable. However, if you?re planning
on using the electronics regularly, they are still recommended to be replaced.The SMD
electrolytics from the late 80?s and onwards often need replacing,. These can leak and
rot out the leads, and being surface mount, they can be quite tricky to replace.
Outside of electrolytics, tantalum capacitors can also fail. Whilst they don?t ?dry out?
as such, they still degrade over time. These can fail quite spectacularly, resulting in
smoke and flames if you are not careful. They are generally more reliable, and probably
not worth replacing across board, but when they do fail, it can be quite impressive.
Other electrical components, such as PCB?s, resistors, and silicon chips, have no
discernable lifetime outside of corrosion and physical damage. Provided they are looked
after, these components can carry on working indefinitely.
Obviously, mechanical components (fans, relays, rotary switches), vacuum tubes, and much
older cardboard tube components (resistors in vacuum tube TV?s/radios) stiff suffer from
degredation from wear and old age. Often replacements can be as scarce as the equipment
itself, so extra care should be taken when powering that sort of stuff on.
On Jan 31, 2020, at 7:22 PM, P Gebhardt via cctalk
<cctalk at classiccmp.org> wrote:
Yep, that's what I call preventive electronics maintenance: I power up for a little
time at least once a year all electronics that were in operational order up to a year ago,
no matter what it is, to make sure they don't turn defective from
"non-running", which is mainly affected by caps indeed.