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Need help identifying an Apple IIe component

Twimfy

Twimfy

macrumors 6502a
Original poster
Sep 11, 2011
888
246
UK
Hi all,

I acquired a complete Apple II from a family friend. It's in pretty good condition but it had been stored in an attic for 20 years without use.

Upon first boot it immediately belched out smoke. Something in the power supply has cracked and leaked some god awful smelling fluid all over the place.

Thankfully the component wasn't connected directly to the board and instead on the 3 pin power socket itself, so no splash damage seems to have occurred.

I've managed to carefully remove it and snap some pics. Does anyone know what it is and where I can get a replacement. I'm 99% certain I can solder a new one in. Thanks in advance:

14wxeed.jpg


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It's a filter capacitor. Extremely common failure these days. Let me start listing the places where this is discussed:
https://forums.macrumors.com/threads/1670186/
http://www.mactalk.com.au/62/116421-apple-ii-power-supply-failed.html
https://groups.google.com/forum/#!topic/comp.sys.apple2/HlktXNMn-70
http://www.vintage-computer.com/vcforum/showthread.php?22720-Power-Supply-Surprise
https://groups.google.com/forum/#!topic/comp.sys.apple2/4SHs_ETi1Ck

Replacement will depend on where you live. Your local electronics parts dealer (Jaycar, Jameco, Mouser, etc.) will have the part you need.
 
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Just make sure that what-ever you get it's a "Class X" rated capacitor. These are designed to go across your active & neutral mains wiring.

You'll be looking for a 0.47 micro farad (uF) 250 Volt AC (or 275V AC) Class X capacitor.

If it's not soldered onto a circuit board (as is the case here), lead spacing doesn't matter.
 
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MacTech68 said:
Just make sure that what-ever you get it's a "Class X" rated capacitor. These are designed to go across your active & neutral mains wiring.

You'll be looking for a 0.47 micro farad (uF) 250 Volt AC (or 275V AC) Class X capacitor.

If it's not soldered onto a circuit board (as is the case here), lead spacing doesn't matter.
Click to expand...

I managed to get a 275VAC 0.47 Class X2 as a replacement. Somebody on another forum recommended it to me before I got any replies here.

Thank you to all of you who chimed in though, hopefully when the part arrives (first class express delivery my ass) I'll be able to get this bad boy up and running.

Oh quick question though, do these things have a set polarity? I only know which way the original part goes on due to photographing the supply before and after. Will it matter which way around the new part gets soldered on?

Sorry if I seem like a total noob who may be about to blow himself up. ICs and circuit boards I'm ok with, power supplies are new territory to me and I generally stay clear.
 
Twimfy said:
I managed to get a 275VAC 0.47 Class X2 as a replacement. Somebody on another forum recommended it to me before I got any replies here.

Thank you to all of you who chimed in though, hopefully when the part arrives (first class express delivery my ass) I'll be able to get this bad boy up and running.

Oh quick question though, do these things have a set polarity? I only know which way the original part goes on due to photographing the supply before and after. Will it matter which way around the new part gets soldered on?

Sorry if I seem like a total noob who may be about to blow himself up. ICs and circuit boards I'm ok with, power supplies are new territory to me and I generally stay clear.
Click to expand...

No problem, that cap will be fine and whilst some capacitors do, these types do not have a polarity to worry about.

Hope it goes well.
 
Well, unfortunately said IIc monitor just went up in smoke.

Not going to try and repair it. Messing about in CRT's is just not my thing. Sad really.
 

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Twimfy said:
Well, unfortunately said IIc monitor just went up in smoke.

Not going to try and repair it. Messing about in CRT's is just not my thing. Sad really.
Click to expand...

I wonder if it's one of the models that had a capacitor's printed overlay the wrong way around. If it hasn't had a lot of use, that is.
 
MacTech68 said:
I wonder if it's one of the models that had a capacitor's printed overlay the wrong way around. If it hasn't had a lot of use, that is.
Click to expand...

Never heard of that. I carefully popped the cover off to see if I could spot any damage internally. Weirdly it looks clean as a whistle which is odd considering how much smoke came out of the thing.

Looking at the smoke damage on the underside of the case, it seems as if it's come from the PSU side of the board but I simply cannot see what has gone pop.

What was really peculiar is that while it was popping and smoking it still happily displayed an image on the screen and it wasn't a burn in either as the programme I was running was still making things move.

I pulled the plug of course before it got worse. I daren't fire it up again incase it catches fire or something.

I'll look again tomorrow during the day with fresh eyes, if it seems like something I may be able to replace myself without dying from a CRT implosion or worse I may have a go at it, or just take it to my local TV repair shop.
 
MacTech68 said:
I wonder if it's one of the models that had a capacitor's printed overlay the wrong way around. If it hasn't had a lot of use, that is.
Click to expand...

Twimfy said:
Never heard of that. ...
Click to expand...

I Don't have access to my old notes but I can recall that here in AU I saw two different chassis of IIc monitor. They were quite different inside. The one that had the electrolytic capacitor fitted backwards made quite a mess inside. I can't recall where I got the info from. Perhaps my notes would remind me.
 
MacTech68 said:
I Don't have access to my old notes but I can recall that here in AU I saw two different chassis of IIc monitor. They were quite different inside. The one that had the electrolytic capacitor fitted backwards made quite a mess inside. I can't recall where I got the info from. Perhaps my notes would remind me.
Click to expand...


The only way I could contest that being the case here is that this display had a lot of use in it's day.

It was used in a pet store to keep customer records, print receipts etc. I'm still in touch with the original owners. So it's likely it would have gone before then.

I think what I'm going to do is run an extension cord to the outhouse and let it run for a bit with the cover off and watch what it does.

I'm also lucky enough to have a TV repair shop in my village (a rare thing in this day and age) I'll pop it along to them if I get desperate although at the moment I'm trying to avoid spending any money.
 
Ok so I dragged it out into the outhouse with the top cover off, ran an extension lead and got a family member to stand by the power socket.

Powered it up and left it running for 30 minutes. No smoke, no explosions and no crackling.

Brought it back in and attached it to the machine and used it for 30 mins again. Seems fine, maybe it was a dust fire after all. All the caps inside look good.
 

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