Thread
Apple II Astec PSU repair, source of paper line filter caps?
Hi,
I recently picked up a beige Apple IIe, which appeared to work but after 10 seconds the PSU started to give out a loud sizzling sound - the computer continued to work.
Open up the PSU case, and I believe the smell/culprit is two "paper line filter capacitors":
- 0,1 uF 250V looks the worst, very cracked and bulging metal sides
- 0.47 uF ? assume 250V ? looks intact, but best to replace
See here for a pic I found of the culprits:
http://www.classic-computers.org.nz/blog/2011-04-28-apple-iie-adventures1.htm
... where can I obtain replacements from? I'm unable to source them, my electronics knowledge is lacking here. As a sidenote, the capacitors look "OK" on the PSU.
Thanks
JB
I recently picked up a beige Apple IIe, which appeared to work but after 10 seconds the PSU started to give out a loud sizzling sound - the computer continued to work.
Open up the PSU case, and I believe the smell/culprit is two "paper line filter capacitors":
- 0,1 uF 250V looks the worst, very cracked and bulging metal sides
- 0.47 uF ? assume 250V ? looks intact, but best to replace
See here for a pic I found of the culprits:
http://www.classic-computers.org.nz/blog/2011-04-28-apple-iie-adventures1.htm
... where can I obtain replacements from? I'm unable to source them, my electronics knowledge is lacking here. As a sidenote, the capacitors look "OK" on the PSU.
Thanks
JB
More research has revealed that I need some metalised polypropolene capacitors, and my local electronics store sell these:
http://www.jaycar.com.au/productResults.asp?MID=1&SSUBID=636&SUBCATID=967&keyform=CAT2#1
... what's the X2 moniker mean?
http://www.jaycar.com.au/productResults.asp?MID=1&SSUBID=636&SUBCATID=967&keyform=CAT2#1
... what's the X2 moniker mean?
When I redid my Lisa's PSU the shop recommended I replace them with polyester capacitors.
I have not had a problem using those.
I have not had a problem using those.
I love researching this sort of stuff, learning more about electronics. I purchased both polypropolene caps as mentioned, and the PSU works a treat. During this process I also replaced the 10V 220 uF capacitor near the heatsink that apparently is a common weak point, even though it looked fine. The old paper caps were cracked and split in several places, when they fail they reportedly give off a terrible smell that lingers for days - thankfully I didn't have the Apple II on for long to work out something was wrong.
That is basically the solution. Use polyester, metallized poly, or mylar caps. They're all essentially the same, for this application.