you can't be sure unless you test it. There are 2 types of bad grounds:

one is a failure to ground to a field (such as the earth or a power grid)

the second is a short to ground

I't's not worth it to me

I used to design and build my own PSU & amplifiers and stuff, but with todays prices it just isn't worth it anymore to go and find out what went wrong inside & repair it.
In a speaker-set everything is integrated, like on mobo's, many components exist out of SMDs, the tiny blocks on your board are SMDs, those can be a capacitor, or a resistor, a transistor, whatever, any component you can imagine.
It's very hard to go change them yourself 'cause in the manufactering process they're damped on the circuitboard, also not many of them can stand the high temperature when welding.
And as he found out his speakers failed, everything else was working fine appearantly.
So prob solved :approve:

well guys it turns out the speakers were blown, got a new set works fine, uncles set worked too, got a new power pack also, before speakers and the old ones didnt work. so once again thx to all

Hey guys , you seem to know alot about speakers
will i've just wired up some speakers to my pc but they get really bad buzzing , for example if i move my mouse i get a high pitched squeak
or if i open a program it dus the same but louder
my pc is windows xp media center edition
:S:S
Please help thanks

mazchaz - the symptom you are describing is common. the only times people complain about it being noticeable is when they have improper volume settings. this problem usually occurrs most with cheaper sound cards or integrated ones.

your volume in windows should be set all the way up, and you should be controlling your volume from the powered speakers.