Smoking from my amp?


Hi,
I have a six channel amp that worked fine until I put it in the box five months ago for building a new room. Last night, I connected all my speakers to it and the left channel didn't work.
After turned on and off a few times to check for which one was damaged (speaker, cable or amp), I saw smoke coming out from the amp and smell something burn.
I opened the cover and see two fuses were blown, but didn't see any burned parts. I plan to replace the fuses and hook it up again. However, my friend told me that's not a good ideas because smoking and smelling burn that mean some parts already burned. He recommend me sending the amp to manufacture for repair because the damaged is more than the blowing fuses. Acording to him, blowing fuses doesn't create smoke, and hook it up again create more damaged.
So, should I replace the fuses and turn the amp on again before seding it for repair? Please advice me
Thank you very much.
DT
worldcup86

Showing 1 response by sean

Replace the fuses with fuses rated for 50 - 60% of the original value. If you have 5 amp fuses, use 2.5 or 3 amp fuses, 10 amp fuses would call for 5 or 6 amp fuses, etc...

If the amp powers up and the fuses for that channel don't blow right away, it is probably safe to hook it up to a "generic" speaker. If no sound comes out of that channel, something in the circuit has blown open. If the amp powers up, the fuses blow right away, something in the circuit has shorted out. If the amp powers up, the fuses don't blow and music comes out of the generic speaker, you're still only part of the way there. Let music play through the generic speaker and check it to see if it is getting overheated. You can do this by feeling the magnet on the woofer. If the speaker is not overheating and you don't blow the fuses after playing music at a very reasonable level, it is probably safe to operate the unit as it is and i'll tell you why.

All electronics have "magic smoke" in them. When someone does something that lets all of the magic smoke out of the unit, you have to take it in for repair so that the techs can put a new batch of "magic smoke" back into the unit. If only a small percentage of the "magic smoke" is let out, the unit will still function. In most cases, several "poofs" of "magic smoke" can be let out before the unit will cease to operate. Since these "poofs" are typically related to careless or just plain "dumb" acts, try to limit yourself to how often you pull such stunts. From past experience, you are FAR better off trying to spread out the "poofs" in small quantity rather than having one BIG "poof" that lets out all of the "magic smoke" at once.

As for where the small quantity of "magic smoke" comes from when you can't really see any visible damage, i have found that it can be tracked back to the masking or "coating" of circuit board traces being vaporized. The traces may still be fine, but some of the coating has "evaporated" or minimized to a great extent. As such, everything still works fine but that circuit trace has the potential for corrosion if enough of the masking has been removed.

The other source for smoke without severe damage would be "critters" that had found their way into the unit while in storage. As such, the "critters" happened to be in the wrong place at the wrong time and made for one helluva big current draw as they were "quick fried to a crackly crunch*". The unit may work fine other than the blown fuses in such a case, but it is better to be safe than sorry and that is why i mentioned under-fusing the unit and hooking it up to a junk speaker first.

If the unit is damaged, put the damaged fuses back into the unit and contact the manufacturer. They can tell you how to proceed from there. Just make sure that you pack it like it's going to be dropped from shoulder height, because it probably will be if you have to ship the unit out. Sean
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* registered trademark of "Cheetos" brand : )

PS... make sure that the unit is unplugged if monkeying around inside it and the filter caps have been discharged.

PPS... As was previously mentioned, i would check out all of your connections to make sure that nothing was shorted. You don't want to find out that the amp is working okay only to do further damage by hooking it back up to what caused the problem in the first place.