Protector flashing

I had the same problem with my 2 year old Sony STR-DB780, all of a sudden it showed PROTECT nomatter how many times I turned it on and off.
Checking the speaker cabling for any shortcuts and eventually disconnecting all cables did not solve the problem.
So I opened the case and disconnected the pcb where the speaker outputconnectors are soldered to. This small board also had the speaker on/off relais (light blue). I disconnected the main connector (white) from the main pcb and turned the amplifier on again: problem of 'protect; was solved ....

So I checked for short cuts in the pcb, removed the dust and made sure the wires (red black black white) were not touching eachother; the isolation can be damaged by the internal heat and the wires are routed so that they touch internal components.

After reconnecting the main connector the receiver is working well again. No cost and hopefully useful to others!

This worked Great. I got this item from work for free thought it was broke. I was about to brake it with a hammer than i thought lets go on the internet and so i did an now it works great.

Thanks
Alot

If you know how to trouble shoot solid stste electronics then sure we can assist you in repairing the unit. If you have a meter then your gonna first have to locate the audio output Ic'S get a service manual and with the reciver on, measure the voltage on the output pin of the IC. If there's any dc voltage at all on that pin disconnect it and check the other side output PIN Also find the b+ pin and disconnect that too. On each output device. Plug in the unit and it should come out of protection. If it dosen't then theres another short in the drivers and they only way to find these is to unplug unit and staticly check each transistor on high ohms to find a leakage. If you Understand what I just said check these items and get back to me as i would like to see the schematic to assist you in what to check next. If you dont then its time for the repair shop as we cant teach you how to do these repairs overnight as this is a timely learning processe and need schooling to learn the theroy and the experience for the practibility of repairing electronics. Good luck

If unit goes into protect mode and stays, it is not a good sign. Either you have a shorted speaker(s) or wires leading to them.
If you disconnect all speakers and you still get protect light, your problem is most likely shorted output transistors /(ICs) and/or drivers. Problem arises form over driving outputs or not enough ventilation when unit gets hot. Just like your car uses radiator to keep in operating range, receiver has finned heat sink that MUST have good air flow to prevent overheating and burnout. This is especially true with high power (100watt +) 5.1 - 7.1 surround per channel amplifiers. Another rule of thumb, never operate receiver/amps in closed rack with unit on top. It will pick up heat from equipment below it

This happens to me too... I have a DTR 5.4... Worked well for a couple of years... Now it is shutting off when I have the volume up too high... Although, sometime it just does it at random.... Very annoying...