BT-693 speaker system

[logan_dslasher]

when i got home last night, my mother was waiting at the porch. she said that the computer blew up!! i found out that it's only the speaker that got damagd. she said it made a popping sound as soon as she plugged he AVR. she said the saw something sparked..

it's still under warranty (i think) so i didn't try to open it and see what's wrong.. i have a BT-693 speaker system. does it have a fuse? maybe that was the only part damaged. how could i check what's wrong with it? let's say i perform a "surgery" on it, where should i start looking for the damage? if it has a minor damage, i want to fix it myself..

i wanted to learn, please help me... thanks.. 

 

[ante1]

Hi Logan,

If it’s still under warranty it might be better not to open it incase there is big trouble inside! 
But if it’s not, be sure to pull the plug before you try to open it! If you open it look for obvious fried or miss colored parts and try to identify whatever looks suspicious! You can always take a picture or two and post them here for further guidance! 

 

[logan_dslasher]

Hi Ante!

i took it to the shop where i bought it for them to have a look at it.. i found out that its not under warranty because it is only a free accessory (pretty good technique - when buying a computer package, all you have to pay is the CPU and monitor, the rest is FREE; though the price is increased for the CPU and monitor  > ) anyway, having them to tell you what is wrong with it even if not actually fixing it will already cost me something.. so i decided, to try (first) to fix it myself..

i already opened it.. it looks pretty clean.. no burnt parts or whatsoever can be seen.. what could be damaged? is it the speaker? am sorry i can't provide a picture of it. i don't have a digicam or a webcam for a screencapture..  it doesnt have any obvious damage..

thanks...  8)

 

[ante1]

Hi logan,

Really smart move giving it away to avoid any warranty!  >
Well, I guess you did not find any fuse inside or outside? BTW does it run of a wall wart or is there an onboard mains circuit? This is a bit fumbling in the dark but we have to start some ware don’t we?

 

[Staigen1]

Hi Logan

How is it powered? If it is a wallwart(or what the name for it is), then it
can be that one that is at fault. Also try to turn up the volume to max,
and take a screwdriver and touch the inputs, if there is some sound, it
shall be some highpitched, 50 or 60 Hz hum, your speakers is probably
not at fault. The input is the wire you connect to the computer(soundcard).
Then it's probably your soundcard that is at fault. And that, i belive is at
warranty. ;D ;D ;D

//Staigen

 

[logan_dslasher]

it uses 220V. i have tried to set its volume to the max but haven't tried touching its inputs.. i'll do that later. i don't think i have a sound card, there's this oscilloscope and freq analyzer i found on the eLab.. and when i transferred the program to my pc an error message flashed.. it said something about the program requiring a sound card.. so i guess i have none..

if i try measuring the speaker with a multitester (R x 1) what should the reading be? can i do that?

 

[Staigen1]

Hi Logan

How is your speaker system connected to your computer?
Via USB ?

//Staigen

 

[logan_dslasher]

aw! i missed Ante's second post.. nope! there's no fuse. that's the first thing i looked for.. BTW whats a wall wart? it has a small PCB inside it, something like 2X2 inches or so.. its where the volume switch and control is placed.

the speaker system has two speakers, just like in the picture i posted. the one with the volume switch and volume control is connected to 220. it's connected to the CPU not via the USB but into a round port..

 

[ante1]

Hi Guys,

logan: You said your mom saw something sparked; can she point out the spot where it came from?

 

[logan_dslasher]

she san barely remember where but she said it's somewhere on the speaker.. she said she probably saw it on the speaker with the volume control..

 

[ante1]

OK, and I suppose this is the same as the one with the mains supply in it?

 

[logan_dslasher]

YES. the one connected to 220 and also to the CPU. the other speaker is not connected to the CPU neither to the mains. a small wire connects the two speakers..

 

[Staigen1]

Ok, do the test i told you, than we know if it is the speaker or the soundcard!

//Staigen

 

[ante1]

Does it have any openings in the back or side like gratings to let the air in for cooling? This is where a spark could find its way out from some rectifier of capacitor when it “exploded”!
Have a close look at the parts near here and remember; do NOT have it plugged in while messing around inside!

 

[logan_dslasher]

none. it's almost airtight. the only "ventilation" it gets is from the speakers' cover. i have an experience once where the capacitor "exploded" i saw a black rubber-like thing coming out from the bottom of its cylindrical casing. i think i saw none, but i have another closer inspection. Yeah, i'm more careful now. last week, i had a "chunk" of my flesh scraped out of my left index finger, then 3 days later my right hand got burned by a soldering iron.. thanks for the warning..  8)

is it possible for a CPU not to have any sound card at all?

 

[Staigen1]

Hey Ante, dont you think he should do this simple test first, before dismantling
anything? Probably it is the speakers amp or psu that is at fault, but you never
know until you test.

//Staigen

 

[ante1]

Hi Stagien,

Maybe you are right; it’s just me being reluctant to power up things that has “exploded” without first try to diagnose it!  ;D

 

[Staigen1]

Hi Logan

is it possible for a CPU not to have any sound card at all?

Of course the computer have a soundcard, else you won't hear anything!
The CPU dont have a soundcard!

//Staigen

 

[Staigen1]

Hi Ante

If the speaker was powered when it happend, and maybee a few hours after that, i belive theres not gonna be more damage to it than there already is!

//Staigen