Hi there,i own a nad 319 amp and when it is turned on it now displays protect on the front pannel,regards andy

If the speakers are all good and wiring too, then it's likely that a fault has developed in the main amp section. Till this is cleared the protection will not go away.

That could indeed be the issue, but you must check your speakers, wiring, and also the oupt stages for problems. Maybe the prtection circuits are actually doing their job. lol

Hope that helps...

Geno

Check the speaker wiring for shorts, a common problem. If everything checks out there may be bad solder joints on the main board especially in the output stage, or there is a fault in one or more driver transistors.

Hello
Check the connection to speaker with this amp, for any short or any other fault. disconnect the outputs, ie, speakers from the amp, and switch it On, and see the protect display comes or not. If it comes, the fault is internal and the set need service.
Your M3 dual Mono integrated amp, is of high output power and its outputs are protected against any overload or short circuit. If the system detect any among this condition specified above, it will show protect mode display.
Never load this amp, as protection display is there, as it may damage the speaker or its internal power amplifier section circuits, may cause more money to get it repaired. OK.

See link below.

http://www.pithed.org/2007/10/12/nad-c370-protection-circuit-repair-amp-fails-goes-into-protection-mode/

I, too, have the 3150 and have experienced problems with it. With me the INPUT knob is touchy and needs micro turns sometimes to get both channels to come through. Also, it sounds like the pots are dirty as I get a scratchy sound while adjusting the knob. I have been told that these units are great middle of the road audiophile units. Actually, for the price of a used unit you can't do better. I just had an NAD 2400 THX amp delivered today and am using the 3150 as a preamp. My girlfriend is not feeling well and sleeping in the bedroom, though, and I can't listen to it :( The few minutes I heard of Steely Dan's Cousin Dupree made me bout **** myself (until I got the dirty looks). Sorry I wasn't more help! Goooooo NAD!

my CD player is Kenwood KDC-W3041 displayed protect and i can't turn it on. what can i do for that?

Having the speaker wires hooked up backwords will not cause protect mode. If the wires were crossed (in other words shorted), that would. Disconnect all speaker wires, if the unit is still in protect mode, than the output transistors are probably shorted and the unit will again require service. Upon return from service, I would turn on the unit without speakers to insure that the unit at least works that far. Also, if you have an ohmmeter, measure across the speaker terminals. You should read either 3 or 6 ohms. If you read 0, the problem is a shorted speaker that then shorted the amp.

Keep us posted.
Dan

Since the problem seems to be sensitive to the volume level, I would be looking at the output wave form for any DC current. Although the protection circuit should detect any DC present, it is possible that some is leaking through. Also, verify that the speaker impedence is correct. If the amp is seeing too low an impedence load, it will work too hard causing excessive heat which will shutdown the unit as well.

Keep me posted.
Dan