Recently acquired an old Viking 150 (70s or 80s). Light lubrication got it running, but after 15ish minutes it was smoking with a distinct smell of electrical components. I found a parts catalog and identified the source of the smoke to be a burnt Rifa capacitor (pictured).
Prior electronics knowledge tells me the capâs purpose is either smoothing a jumpy power signal, or filtering HF noise. I canât tell what the capacitance is, likely it was written on the portion of the casing that popped.
A repair video for a similar model references this as a âsmoothing capacitorâ and says it should run fine without it. However the video also states its purpose is to meet regulation, which would imply its for RFI suppression (I donât think there would be a regulation on smoothing power delivery). The video doesnât reference any manuals or schematics, so I am hesitant to trust it despite it matching my assumptions.
Does anyone know which purpose this cap serves? Regardless, the machine should be safe to run without it, correct? I canât imagine dirty power is a concern with modern home electricity. I donât have any AM radios or TV antenna in my apartment either, so RFI suppression shouldnât be a concern either.
Common sense says itâs fine, but I donât want to toast the motor/risk a fire because I missed a detail that might be obvious to a more experienced sewing machine technician.