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Is the thermistor R1 ? If so, how can this thing blow a fuse with the thermistor open? Unless there is a fault before the thermistor, like VT1 or one of those little caps.
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Originally posted by Enzo
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The 6 pin IC is the loop back from the secondary, That is IC4. There is also the 8 pin IC2, which is where the switching transistor is that I mentioned.
When you test the diodes in circuit, your meter uses a small current to test them. The diodes are connected to capacitors in the circuit, so when you first connect the meter, the small current tries to charge those caps. When you reverse the leads, that small charge now in the caps, is drained by the meter and the reverse process happens. Very normal.
The rectifier diodes need to be fast recovery, do not use common diodes. It is not necessary to use the exact same brand and number, but you do need to use the same type.Education is what you're left with after you have forgotten what you have learned.Comment
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Thermistor is open or SHORTED?Comment
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The thermistor is in series with the mains. If it opens, the circuit stays inert as if a fuse blew. If it shorts, then the start up is less soft.Education is what you're left with after you have forgotten what you have learned.Comment
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The thermistor literally has a hole in it, I am struggling to find anywhere online that can ship it to meComment
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The thermistor can be removed & a jumper can be installed to further the troubleshooting process.
What markings are on the thermistor?
http://www.ametherm.com/Comment
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He said it's a SCK103 and that it measures open circuit.
So like I said earlier, if it's blowing the fuse the fault must be before the thermistor, no?Originally posted by Enzo
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Please use your meter and see if thermistor is really open circuit. If it blew and there's a hole in it, it's possible it melted and shorted. Maybe this is very unlikely, but arcing can cause that. I'd do it just to eliminate that variable 100%. Then move on.Comment
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Part No: SCK-103
Zero Power Resistance at 25°C : 10
Max. Steady State Current at 25°C (A): 3
(25°C Ambient) approx resistance : 0.297
Thermal Dissipation Constant (mw/°C) : 17
Thermal time Constant (Sec.) : 46
Operating Temp (°C): -40~+17
B57235S100M EPCOS / TDK | MouserComment
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I've been advised just to replace the power board? Obviously that's down to the customer and first I'd have to find somewhere or someone that can supply itComment
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