TDA7294 output stuck to -Vsupply

[kroto]

one of my (the farthest from the fan) TDA7294 output stuck to -Vs, why was that?
is it dead? does anyone have the same experience?

the heatsink is pretty small but with a fan, and box ventilation is rather small.
VS +/-30Vdc.


and what is the voltage rating of general brown ceramic disc cap, such as this pic?
[IMGDEAD]http://www.electrokit.com/public/upload/productimage/41758-10793-4.jpg[/IMGDEAD]

regards,

 

[pacificblue]

If the input signal does not lead to that, then yes, the TDA is fried.

 

[Mooly]

The cap is an unknown voltage wise. It could be as low as 16Vdc, more probably 50Vdc but as we don't know for sure....

 

[kroto]

@pacificblue: no input signal, and no Coupling cap too.

@mooly: that would be unsafe to be used as miller cap then.

thanks all.

 

[Mooly]

Without knowing the voltage rating I wouldn't use it anywhere that sees more than 16 volts across it.

 

[JMFahey]

Test it.

 

[JMFahey]

Not forgetting that small value ceramic caps auch as this one, are usually rated for 500V or even 1 KV.
Never ever saw a 16V rated ceramic , althouh in the highest values (such as 0.1uF ) I have used some 25V rated ones.
You do what you want, but personally *I* would use it and not worry a second.

 

[Mooly]

I'm thinking it could be like this,
MCBU5331K5 - MULTICOMP - CAPACITOR, 330PF, 50V | CPC

 

[kroto]

i have been use such ceramic (100pF) for miller at supply ±35V with no failure though.

just curious since some friend say most of it rated at 50v and not blow.

 

[daudinhbl]

Check R 22K from pin 14 (OutPut) to pin 2 (NFB). If you don't connect R feed back, the Voltage at pin output will set to V-.