Hi EEVBlog people
I'm new here, couldn't find the information I needed to check something in the story that follows, then remembered EEVBlog has a forum loaded with people who love electronics
So my story goes I built a computer for a friend of mine 3 or 4 years ago, and purposely had him buy a good quality power supply for it instead of the cheapo junk you can get
long story short the computer died a week ago, and it turned out to be a dead PSU, we have replaced it and all is well
I got to looking at the PSU and thought its such a waste of a high quality PSU, and how did it blow, took it apart, found a Varsistor between the two main capacitors blown to bits, one of those bits had the part no. on it, TVR07241
it was a TVR07241 (240v), not being able to find a replacement for it in NZ, I found a 320v one inside an old dead server PSU(also designed to run on 230v mains) I had laying around, put that into it, and replaced the fuse
It worked!
My questions about this are, is the 320v MOV replacement going to cause it to be non-fire/electrically safe in anyway?(and if so in what ways), and the strange part is, there is another TVR07241 closer to the AC mains input that isn't blown or damaged at all...the one that is damaged is attached to where the 230v/110v switch wire leads in, which makes me think the original damage might be because someone flicked the switch to 110v on a 230v mains supply, am I correct in this theory?
I have a grasp of basic resistors, capacitors and smoothing caps, but no real grasp on MOV's, what I have read up on it tells me they work well as voltage surge protection, and what I can gather from the old varsistor is it protected the power supply from circuit death?
any and all insight into this would be much appreciated