genie_mac
Well-known member
Hi,
I thought I'd post this here as it isn't really machine specific (if there's a better place for it, mods, fell free to move it).
Well I've had three line filter caps (EMI suppressors) fail in spectacular fashion (including that lovely lingering smell) in the last few weeks. These were all PSU's from late 80's to early 90's and hadn't been used in a long time (i.e. years). I think the caps are the metallised paper type, so I was wondering if this kind of thing has happened to others. Are these getting to an age where the dielectric has totally dried up and they are shortening out?
I managed to find a replacement for two of them (your typical modern X2 metallised film cap) but on one of them (IIcx PSU) I couldn't read the capacitance as it was totally destroyed. It just seems strange to me why different PSU's would have such different size caps when they all essentially have quite similar power ratings and are trying to filter similar noise frequencies between the lines. So how critical is the capacitance value here?
Any thoughts?
I thought I'd post this here as it isn't really machine specific (if there's a better place for it, mods, fell free to move it).
Well I've had three line filter caps (EMI suppressors) fail in spectacular fashion (including that lovely lingering smell) in the last few weeks. These were all PSU's from late 80's to early 90's and hadn't been used in a long time (i.e. years). I think the caps are the metallised paper type, so I was wondering if this kind of thing has happened to others. Are these getting to an age where the dielectric has totally dried up and they are shortening out?
I managed to find a replacement for two of them (your typical modern X2 metallised film cap) but on one of them (IIcx PSU) I couldn't read the capacitance as it was totally destroyed. It just seems strange to me why different PSU's would have such different size caps when they all essentially have quite similar power ratings and are trying to filter similar noise frequencies between the lines. So how critical is the capacitance value here?
Any thoughts?