Hi guys,
a neighbour offered me his TV which stopped working, since he knows I like to tinker.
First obvious visual red flag, as a plastic bulging on the back over, not too far from the plug ... I immediately think, something blew up on the power supply board. Here's the pic ....
After I removed the cover (pic below), I am looking at where the bulge is and see obviously one of the green NTC thermistor guys hurting. Using voltmeter to measure ohms, obviously I get out of range figure.
So here are my questions ...
1)
Immediate thought is to replace the NTC thermistor. The value on it reads WMEC
WTR
15D2R5
which I believe means 15mm disc dia., with 2.5ohm resistance value, and 8A peak current, 3.2W power
Problem is I cannot find exactly the same part or value anywhere (anywhere where I can buy few, not hundreds). The closest I am getting is either larger D or a bit smaller peak amps or power. See example below ...
https://canada.newark.com/epcos/b572...mm/dp/24AC7709
My question is is larger diameter bad or it will just dissipate heat better? I assume I cannot go lower on power or amps correct?
Is there a better place then Newark to buy these things?
2)
Not being familiar with the particular component, I wanted learn a bit. It seems that most people suggest that if NTC thermistor blows, it's usually for other reasons than the component being bad or worn out. Having said that, there's no other obvious burnt up spot on the power supply board. Should I be measuring voltages elsewhere on the board to verify whether there's more damage as a result of the NTC failure, or rather something else failing before, causing the NTC blowup. Is it correct to assume that there must have been larger amperage rushing in which the NTC could not take and thus could not dissipate the higher heat value and melted the plastic?
Thanks very much for trying to help.
a neighbour offered me his TV which stopped working, since he knows I like to tinker.
First obvious visual red flag, as a plastic bulging on the back over, not too far from the plug ... I immediately think, something blew up on the power supply board. Here's the pic ....
After I removed the cover (pic below), I am looking at where the bulge is and see obviously one of the green NTC thermistor guys hurting. Using voltmeter to measure ohms, obviously I get out of range figure.
So here are my questions ...
1)
Immediate thought is to replace the NTC thermistor. The value on it reads WMEC
WTR
15D2R5
which I believe means 15mm disc dia., with 2.5ohm resistance value, and 8A peak current, 3.2W power
Problem is I cannot find exactly the same part or value anywhere (anywhere where I can buy few, not hundreds). The closest I am getting is either larger D or a bit smaller peak amps or power. See example below ...
https://canada.newark.com/epcos/b572...mm/dp/24AC7709
My question is is larger diameter bad or it will just dissipate heat better? I assume I cannot go lower on power or amps correct?
Is there a better place then Newark to buy these things?
2)
Not being familiar with the particular component, I wanted learn a bit. It seems that most people suggest that if NTC thermistor blows, it's usually for other reasons than the component being bad or worn out. Having said that, there's no other obvious burnt up spot on the power supply board. Should I be measuring voltages elsewhere on the board to verify whether there's more damage as a result of the NTC failure, or rather something else failing before, causing the NTC blowup. Is it correct to assume that there must have been larger amperage rushing in which the NTC could not take and thus could not dissipate the higher heat value and melted the plastic?
Thanks very much for trying to help.
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