The black part next to the fuse looks like a thermistor MF72 10D9 and and I went ahead and pulled it and measuring with my meter set on ohms it acts as a dead short, actually it is about 10k ohms so maybe it's OK? The blue ones by the fuse are SHM - X1400 Y1250 B471K F and I get a pF reading 46.5 set on the 2000pF range.The 4 blue MOV's in your diagram look like capacitors Y type.
What are the numbers printed on their sides.
Appears to be a black thingy near the fuse. Either a thermistor or Mov.
A shorted MOV generally takes out the fuse, and an open one does nothing .. including no more protection.
And then there is the obvious bad state of blowing itself into nothingness except for the leads left on the board.
I measured it when I first opened this up, I get 120v AC most of the way but after the big diodes I get nothing so it's like there is no DC voltage. I need to solder back some leads and I'll check it all again.What is the voltage across the main reservoir capacitor ? (And what is you mains voltage as you give no information of your location.) Take great care measuring this as it will be a lethal voltage. Also this capacitor will remain charged for some time after the power is removed.
Les.
I also need to know about that MOSFET? How do I know if it's good? It is a smk0460.Are you saying that you get 120 volts AC on the input of the bridge rectifier but nothing on the output ? As you say that the fuse did not blow then this is unususl as diode normaly fail short circuit which should have taken out the fuse. There should be about 165 volts DC across the resovoir capacitor which is normally connected directly to the output of the bridge rectifier. Can you trace out the schematic for the circuit on the input side of the transformer and put it in your next post ? I can only see two of the four diodes that would form the bridge rectifier.
Les.
Hi banjo.The black part next to the fuse looks like a thermistor MF72 10D9 and and I went ahead and pulled it and measuring with my meter set on ohms it acts as a dead short, actually it is about 10k ohms so maybe it's OK? The blue ones by the fuse are SHM - X1400 Y1250 B471K F and I get a pF reading 46.5 set on the 2000pF range.
The veristor is indeed 10 ohms and as it gets warmer it goes down. The blue caps measure a little low BUT my capacitance meter is pretty cheesy and the caps are exactly the same when measured so I think they are fine.Hi banjo.
Your blue ones are caps, 471K would be 470 pF.
MF72-10d9 is a NTC thermistor where the 10 is its resistance valve at room temp 25C, and D9 is the diameter of the devices element. MF72 is it's power rating. ie how much current it can handle without destruction.
It's a NTC, meaning resistance goes negative/decreases when heated.
Dead short means very low resistance(less than 1 ohm), however, you also stated 10k which means 10,000.
Please clarify. Hook up ohmeter, read value, should be 10 ohms, use solder iron tip close by to warm device for a second or so, valve should decrease.
Or even the heat from your fingers would warm it up to lower the value
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