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Macintosh SE: PSU recapping (regular or Low Impedance capacitors?)

G

Gregory K

6502
Dear forum members,

I'm going to recap a Macintosh SE Power Supply (made by Sony). The original capacitors are made by Rubycon, but I can't find any info on them.

Should I replace them with "regular" capacitors, or will it be better to use Low Impedance capacitors?

I would appreciate any info. Thank you!

IMG_6585.JPGIMG_6588.JPGIMG_6598.JPG

 
When I recapped my PSU of SE/30,Capacitor shop in Tokyo(Akihabara) said some Voltage-Rating was eliminated.so you might not be able to find same capacitance-voltage capacitor.but you can use higher voltage-rating ones(ex. 16V -> 25V).Usually voltage-rating gets higher,body of capacitor gets larger,may not fit into board.but capacitor I got were slimmer than 1/4 centuries ago.They were all low-impedance and 105C but not that expensive ones.

 
Last edited by a moderator:
Thank you very much to everybody for your informative answers!

Since using Low Impedance caps in the PSU would improve a reliability of the Mac, I think I can replace ALL capacitors with Low Impedance ones, except the big capacitor (400V 620 uF), which will be replaced by Nichicon GL (400V 680 uF). Am I correct so far?

Also, there are two 350V / 4.7uF capacitors in the high voltage section (please, see the picture, they are black coloured).

Is it ok to replace these two high voltage caps with Low Impedance capacitors as well?

IMG_6601.JPG

 
only the low impedence/low ESR caps are needed in the output section. Regular caps are fine on the line section. 

Low ESR caps wernt used from the factory only if they wernt available, or they wanted to produce them cheaper. But using regular caps do shorten their life, as they heat up more from the ripple current induced from high speed switching. 

However, you can get cheap 85c caps and still be low ESR, or low enough to where the power supply currents wont affect it. But generally as a rule of thumb, the ESR has to be low..

 
Great, thank you very much for your detailed and very interesting info!

If you don't mind, I only have one more newbie question left:

According to Panasonic EB series specifications, these capacitors provide "Hight ripple hight frequency (High Voltage)" feature. With this in mind, is it good or bad to use such capacitors on the Analog Board of Macintosh SE, considering that this board controls the CRT display?

 
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