Overcurrent cut-off??

[stevo1210]

Hello Everyone,

I have a Jarguar amplifier thats made in Korea and is used for karaoke. It's been working well for the last 2 years ago until the party we threw today. At the party we turned on the amplifier for the karaoke and it worked well for about 10 minutes, then for some strange reason it just died out. The microphones will only work at times now.
If someone speaks or sings into the microphone, I hear the amplifier click and turn off and then on again. It will be fine, just as long as no one speaks into it. If I whisper into the microphone, everything seems fine.....
Whats going on here??
I have a feeling a fuse of something is cutting on and off as someone sings/ speaks into the unit. I had a look at the caps in there and nothing is bulging though all of the caps are made by Samyoung.

Thanks.

[Logistics]

Re: Overcurrent cut-off??

Is it hooked up to it's own speakers or did you hook something of your own up to it?

[hardwareguy]

Re: Overcurrent cut-off??

It could be a bad output transistor or a fault in the protection circuit..... or maybe it's just heard too much bad singing and has decided to end it all.

[stevo1210]

Re: Overcurrent cut-off??

Is it hooked up to it's own speakers or did you hook something of your own up to it?

When it was purchased, it didn't have any speakers because it's just an ordinary mixer/ amplifier. It's currently hooked up to a set of Acoustic Reference 400W speakers.

It could be a bad output transistor or a fault in the protection circuit..... or maybe it's just heard too much bad singing and has decided to end it all.

Well only problem is that I have no idea where those parts are located. I'll have to check the internals again next time I go over to my uncles house. It's currently sitting over there because we are trying to test it on another set of speakers....

[999999999]

Re: Overcurrent cut-off??

I second the idea that it may be a blown output transistor. These are typically located on the largest heatsink. A good picture of the internals or as much of a description of them as possible might help.

If it's more integrated, or if the transistors seem ok, you may want to trace backwards from the OCP circuit, it may require pulling the whole board out to do that.

[stevo1210]

Re: Overcurrent cut-off??

Um.... yesterday afternoon I discovered that the right speaker cable had short circuited where the speaker was....

I seperated the shorted wires and voila! it worked again!.

Oh great, now I sound like a fool. .... But then again, I learnt something new.
Just to make matters worse.... now the DVD player that plays the Karaoke discs won't read anything....

Thanks for your help guys!!

[starfury1]

Re: Overcurrent cut-off??

make sure you haven knocked any of those flat cables out of whack when you pulled it apart....easy done considering the way they build things these days

Yeah the closest thing to a short circuit an Audio Amp should drive is a speaker...
We live and learn
if Its an IC amp as I suspect it is it probably had short circuit protection..