capacitor burst

[shamikrudra]

hi
i have corected all the problems in my 230W AT SMPS
and make it on and check there is only 0.33 V in 5V out put
after a moment new capacitor of 300 uF 250V burst there are two same value capacitor
what can be the problem what should i check first?

Regards
Shamik

 

[Optikon]

hi
i have corected all the problems in my 230W AT SMPS
and make it on and check there is only 0.33 V in 5V out put
after a moment new capacitor of 300 uF 250V burst there are two same value capacitor
what can be the problem what should i check first?

Regards
Shamik

If it doesnt have an over voltage problem or a reverse polarity issue, calculate the ripple current for the capcitor and see by how much you are violating its specifications.

 

[Styx]

Yup 2nd that on the ripple current.

If it was over-voltage or reversed they would go straight away.

However, with ripple current it is the thermals that kill it. When the cap warms up its voltage rating reduces, so you end up killing it via overvolts eventaully.

Is it near anything warm?

 

[eblc1388]

The two posters are correct about capacitor damaged due to high ripple current.

The most likely case is shorted AC input rectifier diodes or rectifier bridge.