Blown cap in Macintosh Plus PSU

[UraBahn]

I had an old (and I mean real old) Mac Plus with a blown Samyoung Chemi-Con 100uf 200v capacitor on the power supply. It seems that the capacitor is just a standard 85d cap, ie it's not high ripple or low ESR or anything like that. I was just wondering if it would be safe to use a low-profile or miniaturized replacement cap in its place? (It's a 16mm 'full-size' cap)

Thanks,
UraBahn

[AK0R]

You absolutely *DON'T* want to do that. The problems with Mac and Mac Plus power supply capacitors were well-known and documented long before the current issues surfaced. The problems were due to using 85 C units, rather than the more expensive 105 C caps, and the fact that the original Macs had no cooling fans. I bought a Fanny Mac (fan that fit within the handle area) within a month of buying my 512k in 1986, because it ran so hot (maybe still available on eBay?). It still runs just fine, and I've never had to replace the caps. The recommended replacements were Nichicon or Panasonic 105 C caps, the largest that would physically fit the area (no spec on low ESR or high ripple) to provide heat dissipation capability. The books written about it at the time recommended replacing all (eleven, if memory serves correctly) large electrolytic caps with 105 C caps at once, so that you don't have a problem with new parts placing extra stress on old parts.