Fault light on no sound to speakers removed cover blew out heavy dust system played 3mins then fault light came back on,its a crown xls 402 plz advise!

Got the same problem on my amp right now.
Trough the schematics i could see that transistors bc184l & bc214l could be the cause in my case. If i turn it on, it can be ok for hours. Untill i turn up the knob with a speaker connected, in 30 sec it shuts down. The PTC on the rectifier board gets hot and also R21&R23 a bit. I will try to change the 3 pnp/npn and also tip50G.
I'll tell you how it will be...
One Love
Cesare

Hello
surely there is some short circuit inside you amp, which causes heavy current flow, when you switch On it now. The main cause of this type of fault is with shorted audio output section inside the printed circuit baord. will have any shorted Integrated circuit [IC] or power transistor or MOSFET.
Your amp need service. Never switch in ON, until the fault has been rectified, as it may cause more component to be get damged.
Get it serviced by any expereienced service technician, as this work is skilled one, must have thorough knoledge in electronics, all tools to do the work, ability to loacate the faulty component etc. If you have all these, inform me. I'm happy to assist you further. The more you need is patience and concentration. OK.

Get the manual out and read page 6 - 7 to find the exact light pattern you're observing. The 'fault light' (singular) flashing is not a documented possibility.

http://www.retrevo.com/support/Crown-CTS600-Amps-manual/id/22150bh342/t/2/

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 '*****'. If it comes up then diagnose which lead(s) are shorted. If it does not come up the problem is internal and should be left to an experienced and competent hands-on tech.

I'm assuming you mean he plugged an amp output (meant for a speaker) into the input of one of the Crown amps powering the sub-woofer. Right? Crown amps have good protection circuits and are high quality units. Some models have internal fuses but you didn't list a model here. If they are fused (or some kind of breaker) you should be able to see those by opening the top cover (amp off and unplugged). It is unclear if you tried to use the amp again after this incident.
Some Crown amps have protection circuits that will reset themselves after the fault is removed. In this case, you should remove both inputs and output (speaker) and power it up. If the amp doesn't light any protection lights or indicators, then turn it off and connect a known good speaker (not the subwoofer) and a source you can control. Set a low volume and see how it goes. You can really try either approach first depending on what's easier.

Chances are you have a failure in the final amp stage.

Check the voltage on the buss where the output transistors merge via the equalizing resistors. The voltage here should be very near zero.

Every time i have this prob i've blown that channel. In my case i,ve had dodgy connections to my speakers and if it is operating with high voltage rails they don't take much to blow.
Take off cover and you will no doubt find fuses somewhere blown. If it has come from speakers you prob done the amp but if not you might be lucky and just have to replace a single fuse or so.Good luck,Paul

check for any speakers is disconnected or short circuit.

Hi try disconnecting the speaker outs and turn off bridge (if its on) If it doesnt work still, then suggest direct to a crown agent. The amp has a 3 year no fault warranty. Hopefully its still in!

All the best

Hi there. Check for shorted speaker wires. (chews) Also, remove cover and blow dust out.
Thanks
Paul

Power Output (1 kHz*) Stereo Bridge-Mono 8 Ohm 4 Ohm 8 Ohm XLS 802 500W 800W 1600W XLS 602 380W 600W 1200W XLS 402 300W 450W 900W XLS 202 200W 300W 600W *1 kHz Power: refers to maximum average power in watts at 1 kHz with 0.5% THD. It depends on the impedence of the speakers. Carfull as you could burn up this amp if you exceed the resistance rating on it. Go here on all of the specs of this model of crown amps. http://www.crownaudio.com/amp_htm/xlsspec.htm Good Luck