Probvlam with my cambridge audio 640 a cutting out
When i play any music at quite high volume it plashes 3 red dots and cuts out, the amp is hot but its not the warning for overheating. I originaly thought it was a problem with my amp but this is the second amp after getting the first one replaced. Could it be a problem with my speakers. They are correct power and ohms. Thanks K
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Re: Probvlam with my cambridge audio 640 a cutting out
Check operations manual for indications as you described. Amps MUST have adequate ventilation. Make sure unit is not in small, semi- closed space or on top of other warm equipment. Check for speaker impedences match that of amp
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You seem to have the answers to your question. I would just resolder the connections anyway without checking. If it solves the problem you have saved yourself a lot of money. If it doesn't follow the other steps in order of cheapness!
The protection only should come on, when the power amplifier has to give more current than it can deliver. (electronic fuse) If in the music is a lot of subsonic, sound, so low you can't hear and your speakers can't produce, this could cause the problem. Normal CD players will cut of all frequencies beneath 20 Hz, but it could be your PC is giving everything from 1 Hz and above. I would certainly try to play some music over a CD player and check if that would solve your problem. Not sure if that works, what you could do to suppress the sub sonic in the computer music.
The capacitors in the power supply might indeed cause the humming noise. This could be the 50Hz mains hum getting in.
I can't tell you if having four amps on top of each other is the cause of the problems your experiance. What I can say is that anything running at temps to fry eggs is a fire hazzard. And that might mean extra cooling is needed if you want to be safe. You should also check each amp. I would do this by seperating the amps to see if one of them is making more heat than the rest. If that is the case then you might have a part - a semiconductor - that has a thermal problem. The capictors will fail if they are having to deal with excessive heat also, that's if the amps don't burn the house down first!
Generally speaking, an amp attempts to protect itself from heat, shorts, overloads and operator exuberance by refusing to turn on or stay on.
Overloads can be from excessive periods of high output or marginally low impedance loading by the speakers; and shorts would be wiring issues or a speaker blowing up.
You should be able to feel if it's hot. WHY is it overheating? Make sure it has sufficient ventilation on all sides and that vent holes are not blocked by dust balls. Ensure the fan (if equipped) is running as designed (some only operate on demand). Clean dust and debris from it.
If the amp comes back on after cooling, you're lucky. They only have so many self-protection cycles in their lives so continuously resetting or cycling their power without addressing the cause can do more harm than good.
If it protects immediately on a cool power up you should disconnect the speaker connections and try it 'naked'. If it comes up then diagnose which lead(s) are shorted or, again, evaluate the impedance load. If it does not come up the problem is internal and should be left to an experienced and competent hands-on tech.
Check for loose speaker connections at the speaker as a possible root cause for intermittent shutdown.
Yes, you are right. That's a protection feature to prevent burnouts. Typically it appears when your speakers are sucking up a lot of load from the amp. Please check your speaker impedance and the amps' output impedance and ensure the wiring are properly done. Some amps are soo sensitive that they may cut-off after certain level due to overload.
Use a multi meter,set it to 12v,turn system on use some bass.while music is playiing hold pos of multi meter to poss- neg to neg- on amp see what voltage is running at at what its dropping to it sounds more like a voltage drop problem.if you hooked it up back words u could fry unit..Have you done the big 3.what size is your alt,and what is your amps draw..