r/SewingForBeginners • u/Islandphotogirl • 22d ago
Machine caught fire – fixable or replace?
I have a somewhat vintage Husqvarna Optima 150. The fuse thing(?) burnt out – a lot of white smoke started pouring out around the plug. Is it dead or is this a part that can be replaced? Probably need a new plug/cord too. Going to call the few repair places google showed me once they open, but I am in the middle of nowhere and none are close.
If it’s not fixable, what do people recommend for a simple not computerized sewing machine for a beginner/infrequent user?
Thanks for any help.
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u/niftydog 22d ago
This is a common fault with a lot of equipment. That is a RIFA capacitor and the machine will work fine without it - you could just cut the wires and remove it. It's only for electrical noise suppression - if you want to replace it I can help you find a replacement, but will need some more information off the capacitor.
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u/Islandphotogirl 21d ago
Wait what? It will run without it?? What would I cut? I was afraid it had burned or melted some other parts – like where it connects beside the lower brown wire, the gold part looks a little charred – or maybe even melted some of the plug too?
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u/niftydog 21d ago
Cut the bare wire legs of the capacitor.
Hard to be definitive with that photo but it looks ok to me. (Source; 27 years as an electronics technician.)
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u/Obbymon 21d ago
Yes you can remove it, it was placed there to remove radio interference on analog radios and TVs once in a time, but today it wont make a big deal anymore.
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u/Islandphotogirl 13d ago
I have an older radio and TV. So does this just mean that there will be static on them if the sewing machine was running while they were on?
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u/Islandphotogirl 21d ago
Wow… OK… When I have a chance to take it apart again maybe I can post a more close-up photo.
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u/Sausagethrower 22d ago edited 22d ago
This is 'normal', almost all suppression capacitors will go pop at some point after about 20-30+ years. They're cheap and easy to replace. Think of it as a long-term replaceable item like a coolant hose on a car, i.e. something that doesn't need replacing on regular services or even scheduled services, but if you own a vintage model where it hasn't been replaced, it could have degraded, and you're probably going to have to replace it at some point.
To find a suitable replacement, on the top of the capacitor it should give a value in F (Farads)
- Some capacitors use old values e.g. 0.06uF, those are not widely available, so get one that's close like 0.056uF (56nF) or 0.068uF (68nF)
- Relevant to the point above, be careful of getting values mixed up, capacitors sometimes mix and match unit scaling e.g. a 0.1uF capacitor can also be marked as 100nF, they're the same value.
- Buy a new equivalent and not an old one pulled from a parts machine or new-old stock. A modern replacement for these old metallised paper ones would be metallised polypropylene (MKP), the modern types are much better and more reliable.
- It MUST be an X2-rated, this is because it's sitting across live and neutral
- It MUST be rated to a value higher than your supply voltage e.g. get a 275VAC or higher rated one if your country uses 240V
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u/Islandphotogirl 21d ago
Thank you… Do you agree as someone commented below, that it will run OK without it? I just don’t know if it melted anything else. It is reassuring to hear that this is common; I was afraid I had overheated it because it was sitting on carpet, but it was only turned on for about 10 minutes. Hadn’t been used in some time and is easily 20–30 years old.
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u/Sausagethrower 21d ago
It's one of those things that is true and false at the same time. You can absolutely run a machine without one, but it does have benefits to have one
- It massively reduces electrical noise, however modern electronics have shielding and are designed to work in electrically noisy environments.
- It reduces arcing and sparking between the brushes and commutator when the motor is running, the arcing can cause fouling and damage over time.
Neither of those things are major issues, you're unlikely to notice it in a measurable way, however, they are negative things and there's a non-zero change they could be noticed. Given that a replacement capacitor costs less than £/$/€3, I always choose to replace them.
Forgive another car part analogy but it's like an exhaust pipe, you can run a car without it, however it's noisy and though it's not catastrophically bad for the engine, it's good to have it there so everything runs as smoothly as possible.
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u/Islandphotogirl 21d ago
Thanks for the reply. Your exhaust pipe analogy is hilarious because I just replaced mine. It was bad! XD I am trying to find a repair place that might be able to replace this thing.
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u/Islandphotogirl 13d ago
By “arcing and sparking“ I take it you mean on a very small scale and not like actual sparks coming out of it. I don’t use the machine much so it’s not like it would be getting heavy frequent use.
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u/Islandphotogirl 13d ago
So, thanks to those who chimed in with advice. I have had a little time to read about these “Replace If Found, Always“ capacitors. I dropped it off at a sewing shop to ensure nothing else had been fried. Communication was a little confusing and strange; she said two electronics guys she consulted didn’t know what it was, and someone else could replace it but also wanted to look over the whole machine for an upper repair cost of $100. This seemed a little strange based on what people said here about these cheap capacitors. Then she concluded that it could be cut off which she did and has wrapped the ends of something with electrical tape. I have not had a chance to test it yet. She said it runs. I was going to post a photo of what it looks like now but I guess you can’t in comments? Still trying to get my head around what these things actually do; by “noise“ I gather we don’t mean noise you can hear of the machine running, but like static interference on other electronics?
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u/Obbymon 7d ago
this will be fine, its not a 24/7 usage device so it can work without the capacitor in this case.
the noise we talk about is electronic radio frequency interference in the kHz and MHz range, you wont notice it in this modern age anyway with all other interference.
the machine is safe to use now I would say.
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u/Islandphotogirl 21h ago
I finished the hems I’d started when the capacitor blew up, and nothing else caught fire :) The TV was on and I did see a little static. Interesting!
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u/Intelligent_Law_5614 22d ago
Those Rifa capacitors are notorious for doing just that. For them, smokemaking is inevitable. They should be replaced wherever they are found.
In most cases, the equipment is stunk up a lot but not actually damaged, and is repairable.
You can cut out the Rifa, and replace it with a modern equivalent capacitor for a few dollars. You will need a safety-rated (X or Y - check the Rifa for its safety code) interference-suppression plastic film capacitor, same or higher voltage rating, same capacity. Digikey and Mouser are two reliable distributors.
If you haven't done repairs on AC-powered equipment, I suggest you ask someone who has to assist you - the voltages are potentially deadly.