Help when i turn the onkyo tx-sv454 on it gos in to protect mode then turns off

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. 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 another possible root cause for intermittent shutdown.

This means that you have a problem with the speaker outputs.
-Try turning the unit off and unplugging it.
-Disconnect all of your speakers.
-Plug it back in and turn it on.
If it works, check you speakers and wiring for shorts.

If it still shows protect then you probably have a blow output amplifier and it will need repair.

I don't think you can fix it, unless you're skilled with electronics. Possibility that something has occurred internally with a circuit board etc so the system shuts down in order to protect itself from catching on fire etc. Get it services. Might not be too bad of an issue, but certainly not a bypass.

This unit is in protect mode. This means that a problem was detected and the unit has shutdown to prevent further damage. The most common cause of this is failed output transistors. Plan on $20-$40 for parts for this repair.

Dan

There's a fre service manual here, you need to join tte site (free)

Onkyo TX SV727 Manual AV Control Receiver HiFi Engine

Generally, this happens when there's a loose connection somewhere, either internally, or with the connections. It usually happens when the volume's too loud, and it tries to protect itself.

I'd suggest you unplug everything from it, check all the speaker wires, and then try turning it on, without any devices connected to it.

If it works, turn it off, and reconnect devices, one by one. That should fix it.

If not, it's likely that there's a loose solder inside, and it needs to be sent out for service.

I was able to solve this problem by using the "A" speaker jacks and eventually I pushed the right buttons to get the Surround mode to turn ON. I believe it was when I hit the Parameter Selection button that allowed the surround mode to become active.

the shorted spkr wires probably fried the putput transistors in that channel.  Do you know how to use a Fluke  test meter on diode test

Hello.You have shorted audio outputs. One of your channels has shorted output transistors. If your unit uses output ICs then one of them is shorted. Both types ( individual transistors or ICs ) are located on the large finned heat sink. The parts are available from http:\\www.tritronicsinc.com. good luck

barneyluc

i believe protect mode is because you have the wrong impedence speakers, they are too low (4 ohm? 6 ohm?) it chols work with 8 ohm speakers