My early Apple II PSU is weird (820-0003-01) - RIFA caps nonexistent?

• The white-ish box on the bottom right on our PSU is not a cap at all, it's a resistor
• The two big brown flat caps in the top right just say on them:
  • 225K 250V
  • 105K 250V

The PSU has an NTC thermistor at its input, which is normal.

Those brown RFI caps are polypropylene film, not ceramic. 2.2 µF ±10%, and 1.0 µF ±10%. These values are very high, and will cause significant leakage current at the power point, which might trigger a GFCI or RCCB. The most common Astec model AA11040B uses 0.1 µF RFI capacitors.

Taken from the linked thread, is this a picture from your power supply?

The class X capacitor is hidden away inside that metal can at the IEC power inlet, but it might or might not warrant replacement depending on whether it's a paper film vs poly film capacitor.

Class X cap inside 820-0003.png

There's a lot of potentially-misleading lore about class X capacitors and whether they need replacement, but there's no harm in replacing it if you're unsure.

• Class X capacitors are required to be installed inside a non-combustible enclosure to prevent a fire hazard.  Your PSU just happens to use an IEC power inlet that has its own metal enclosure, whereas Apple's later models rely on the aluminum box as the enclosure.  This has nothing to do with whether that capacitor actually needs replacement.
• If you can identify the capacitor as a paper film or metallized paper capacitor then it should be replaced, even if it's a non-RIFA brand such as WIMA or Vishay.
• If the capacitor is labeled with the letters "MP" then it is a metallized paper capacitor and should be replaced, even if it doesn't have the "RIFA" brand printed on it.
• If you can positively identify the capacitor as a polyester or poly film capacitor then it doesn't need to be replaced unless it has actually failed.

Here's the data sheet for that 6EF1 Power Inlet, but it doesn't disclose whether the capacitor is paper or polyester.  It doesn't look like it was intended to be opened and serviced, does it?

geerlingguy wrote:

Those other large brown flat caps that are not accounted for seem to be mylar film, and the jury's out whether they 'should' be replaced, reading through some vintage audio forums.

They don't need replacement unless they fail -- just like when they were new.

Although any class X capacitor could fail explosively, the "exploding RIFA" problem is actually an unplanned problem with paper capacitors.  The film inside a capacitor is supposed to function as an insulator, but we now know paper can become conductive as it ages.  With the capacitor connected across the power line, unintended leakage current causes heat or pressure to build up until it ignites or explodes.  Not intended.

This problem isn't unique to RIFA capacitors -- RIFA just happened to be a common brand of paper capacitors in vintage computers.  In the vintage radio community the leaky paper capacitors tend to be other brands like Sprague or Sangamo.