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Is this a capacitor or a varistor? How can I figure out specifics?

  • \$\begingroup\$ Just a safety note: Even if you find a replacement type (which would have to be an exact type), you will also have to make sure you can safely remove the metal deposits (burn marks) from the board and the adjacent components. Also, make sure that the enameled wire on the choke is still in good shape. \$\endgroup\$ – zebonaut Sep 20 '20 at 21:02
  • \$\begingroup\$ IMO the varistor are the two blue pancakes above. So it must be something else. Maybe a resetable fuse which over-reacted. Or a low cap capacitor. \$\endgroup\$ – Fredled Sep 21 '20 at 1:06
  • \$\begingroup\$ @zebonaut It depends what it is. For many components, the exact match is not necessary. You can even find higher quality components. If it's a protection device, it doesn't matter too much. More important is to isolate the cause of the failure. \$\endgroup\$ – Fredled Sep 21 '20 at 1:09
  • \$\begingroup\$ @Fredled The blown part is in the input circuit. My guess is that the heat-shrunk components next to the fuse might be varistors or Y-caps. The two blue components next to the blown part could be Y-caps because the board markings say CY, if I read correctly. The blown part could be an inrush-limiting NTC. Those blow because of ageing or because of a short downstream. Any Varistor or EMI cap (CY, CX) will be a "critical component" during certification and important things like isolation spacings depend on them. Replacement parts must fulfill the original intentions, which may not be obvious. \$\endgroup\$ – zebonaut Sep 23 '20 at 20:34
  • \$\begingroup\$ @zebonaut The CY marking is for the grey rectangular component ine step firther which are high voltage caps. To know what the green litle thing was we would need to see the marking and a close up of the part removed from the board. And a hand drawn shematic of the connections between components.. \$\endgroup\$ – Fredled Sep 23 '20 at 21:18

This site does allow questions on identification of components but we need to see the markings. You may need to remove it from the board and clean it up. Alternatively you could search for a service manual which has the schematic and then you just need the reference printed on the board to which component this is.

You’d have to be very fortunate to have someone on here that happens to know that board from their experience and therefore knows what that component is and we don’t like to guess here.


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