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Replacment power supply capacitor

Lurch666

Experienced Member
Joined
Dec 14, 2010
Messages
190
Location
Stoke-on-trent. U.K.
My PET recently had a failure with it tripping the mains and smoking a bit.It looks like the smoothing capacitor in the PSU has failed.

2013-10-23 11.58.42-1.jpg

I have looked around and cannot seem to find a replacement.
Any idea where i might get one or is there a modern workaround.
I really don't want to have to replace the whole PSU.
 
Im by no means an expert, but as long as you replace it with a similar capacitor is should work just fine.

I can only speak for modern electronics, but I dont see why it would be a huge issue.
 
That's the line filter which is on the mains side of the transformer. They are more commonly found integrated into the power socket these days. Search ebay, digikey for 'IEC line filter' etc and you will find plenty. I don't know whether such integrated modules were available in the late 70's and as most PET's have the cable directly wired into the PSU, thats probably why.

The ones like you highlight can make an awful mess when they fail and this happens often to the ones in PET's and the B/CBM-II Series. Personally, I just remove them from the B-series when I first open the case and from PET's if they fail. Commodore always struggled with FCC certification and I suspect this is why its there.
 
That's not a capacitor; it's a mains EMI filter, designed to keep stray signals from the computer from interfering with radio reception. You can find them nowadays integrated into the mains receptacle. Schaffner might have some varieties that are adaptable to your use (I'm guessing that you're writing from Europe, although you don't say).
 
Is it something I can run the PET without?
It's wired to both the live & neutral connections and the other connections go to the fuse and the transformer so I'm unsure how to remove it because some of the connections will have to be bridged.
 
Is it something I can run the PET without?
It's wired to both the live & neutral connections and the other connections go to the fuse and the transformer so I'm unsure how to remove it because some of the connections will have to be bridged.
In my experience, yes, it will be fine without it but if you are not completely comfortable working around mains voltages, I would find someone local with some experience who can do it for you.

cheers, Rob
 
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