Do NTC inrush limiters wear out?

[John843883]

After having a TV power switch wear out and arc I'm wondering if its possible for those little NTC inrush limiters to wear out too and allow more inrush current to flow from not acting fast enough or its values drifting over time. The TV is about 8 years old and its a 42 inch CCFL backlit with a large 220uF input filter capacitor, mains voltage is 240v.

Is this possible or am I barking up the wrong tree?

[R_J]

Re: Do NTC inrush limiters wear out?

I have seen ntc's go open but not really wear out. Its likely the switch just went bad, I've seen that before. just a cheap switch.

[japlytic]

Re: Do NTC inrush limiters wear out?

On a related subject, the "on" resistance of PTC resistors will increase to the point where it will be unusable every time the maximum current is exceeded.

[John843883]

Re: Do NTC inrush limiters wear out?

I have seen ntc's go open but not really wear out. Its likely the switch just went bad, I've seen that before. just a cheap switch.

Was it a Toshiba TV by any chance or did the switch look like this one?

On a related subject, the "on" resistance of PTC resistors will increase to the point where it will be unusable every time the maximum current is exceeded.

Good to know, thanks.

[budm]

Re: Do NTC inrush limiters wear out?

TV uses NTC for inrush current limiting, not PTC.
NTC: it will have resistance rating at 25c, this resistance value is the one that limits the current when the TV is first turned on, as it is heated up the resistance will go down.
Typical values uses in is between 5 ~ 8 Ohms range.