This thread has gone on for a while and I think we all get the points here, but one other consideration - how will removing and replacing a component damage the board? Damage the board and it's game over. One should always take the overall board's ability to handle replacement. With the board in mind, I avoid any part replacements and try to keep them to what is proven necessary only.
On Wed, Jul 22, 2015 at 8:18 AM, tony duell <a...@p850ug1.demon.co.uk> wrote: > >> > They reliably do what they're supposed to do. >> >> You didn't answer the question. How do you know those aluminum >> electrolytic capacitors are functioning just as good as they did when they >> were new? Unless you've tested them out of circuit, you simply cannot make > > That, actually, is the wrong question to ask. You should ask 'How do you > know if these old capacitors are working as well as the brand-new replacements > will'. > >> that assertion. > > I think he did answer it. If the unit is operating correctly then the > capacitors must be > sufficiently good at that time for that unit. > > Now, whether they will go on working is something that is very hard to tell. > But that applies > to every other component in the unit. An IC might work find now and suffer > bond-out wire > failure later on the same day. > >> Just like the NiCd and SLA batteries I mentioned, aluminum electrolytic >> capacitors by their very electrochemical nature degrade as they age and as >> they are used. You cannot claim that a 20-30 year aluminum electrolytic > > Semiconductors also degrade both with time and use. I would think a > 30-year-old > 3 terminal regulator IC was also beyond its design life. So do you replace > those > 'anyway'? The damage done if one those fails is likely to greatly exceed the > damage > done if a capacitor fails. > > Do you replace all EPROMs in case they develop bit-rot (They are most likely > way > beyond their design life by now)? > > -tony -- Bill vintagecomputer.net
