filter recap issue

[mor2bz]

Hi all

I just attempted a recap of the 4700 uf 50v filter caps in a harmon
kardon 730 receiver. I had just done another one successfully but
failed with this one. the second one i did had 50v caps the first one
had 35v caps.. .. so of course i had all 35v caps that i had ordered and
stuck them into the 2nd amp. the last cap bulged and went up in
a puff of smoke. i believe i had it wired right.

is this small diff. enuff to fry it or did i wire wrong? thanks in advance

[jaycee]

If the originals were 50V then this implies the power supply voltages were probably 40-45V, so yes this would smoke 35V capacitors.

[stratus46]

Originally Posted by mor2bz

Hi all

I just attempted a recap of the 4700 uf 50v filter caps in a harmon
kardon 730 receiver. I had just done another one successfully but
failed with this one. the second one i did had 50v caps the first one
had 35v caps.. .. so of course i had all 35v caps that i had ordered and
stuck them into the 2nd amp. the last cap bulged and went up in
a puff of smoke. i believe i had it wired right.

is this small diff. enuff to fry it or did i wire wrong? thanks in advance

You put in 35 V caps in place of 50s? That's as bad as reverse polarizing them. Main filter caps are often run right up against the wall so there is little to no wiggle room. Either way they bulge and go up in smoke. You can _sometimes_ use a lower Voltage capacitor IF the rating is greater than the actual run value. It's poor form and not recommended regardless but I've done it in a pinch. You can always run a higher voltage capacitor but you might run into size difficulties.

G²