SONY TA-N77ES POWERS ON BUT PROTECTION LIGHT STAYS

I have seen the higher power cb's fry the fm front end sectioon of the tuner section....did you try to put it on an aux input?....the click you hear is the amp protection relay and it sounds like it is working ok....if it were the output side of the power amp, then the relay wouldn't click after power up...it is probably the front end...this is the entire fm tuning section usually contained inside a metal box near where the antenna comes in

The click you hear is most likely the speaker protection circuit relay due to the protection circuits being triggered. In the event of a dc voltage appearing across the speakers the protection circuit isolates the the speaker terminals from the output stage.
Dry joints on the relay is not uncommon and causes false triggering. Check both pos' and neg' supplies are present at the output transistors / ic. Connect a dc volt meter across the speaker output terminals if a voltage of more than a few millivolts appears just before relay clicks then check the ouput stage for dry joints, leaky transistors and resistors having increased in value.

Hi the protection light comes on when there is a problem within the amps. circuitry. Generally speaking the protection light normally comes on when powered up while the amp checks all of its voltage rails so that they all lie within a specific tolerance, when all have been verified to be in spec. then the protect light goes out & the power light comes on. If the protect light stays on then a fault exists within it's circuitry. Cheers, acbva.

Do you hear any clicks? If not, the standby transformer or related circuitry is bad. If you hear 1 relay click...the audio output section is most likely the problem. The first click you hear is the main power relay...and should see display.. the second relay click is the protection circuit relay engaging to let audio to your speakers...if the second click is not heard (it should occur in 3 to 5 seconds) there are shorted output transistors or a shorted output IC trying to blow your speakers with 50 to 75 volts dc. The protection circuit monitors the speaker lines for voltage. They should always read milli-volts only...not even 1 volt.Anyway, good luck

These units have protection circuits that will prevent the speaker relay from engaging if there is a problem detected. There is also a circuit that causes a delay in the engaging of the relay to allow the amp to "settle in". This prevents the old "thump" that was common in older models when the set was first turned on. In your case, either the RC circuit is faulty causing excessive time to pass before turning on the relay, or there is excessive voltage floating around that the protection circuits are detecting and thus preventing the relay from turning on.

In any case, this will require additional diagnosis using some test equipment. This is not a problem that will be easily resolved remotely. Please bring this unit to a repair shop for an estimate. Once you have that info, we can assist with the actual repair.

Dan

Hello mcis43fan,

The protection circuit can be activated by shorted or grounded wiring or it can be caused by a defect in the amp itself.

First, disconnect all wires except power, ground and the remote turn-on lead and see if the amp powers up normally. If it still goes into protection, the amp is defective, most likely shorted outputs and needs repair or replacement. If the amp powers up normally, test the other wiring for shorts and grounds. You can reconnect them one at a time to determine which one is causing the problem.

Hope this helps.

check your subs disconnect them the try to power the amp up if it powers up the the subs have died and it could be a problem with that amp i suggest you get a better amp

Sounds like you have an ohm problem, Tryy hooking the positive from one speaker to the negative on the other speaker. Then hook the negative from the first speaker to the negative on your amp and the positive from the second to the positive on the amp this will drop your ohm load and the amp should stop going into protection.

The blinks can tell you the problem , is it 4 blinks that could be 3 different ics IC1509 Q1505 or IC502