Protection circuit activates after few seconds. Relay clicks. Display does not work. What elements are likely to be damaged due to overheating? What should I test?

Image gallery:

http://imgur.com/a/BDQNI

 

sounds like its the speaker protection relays, or de-thump circuit, i would say its the two ic modules that are blown (long black chips bolted to heatsinks) with white compound on

 

Ah, I hope ICs are alright as 2 of those cost more than used receiver.
Is there a way to test them?

 

only by swapping them for new ones..

you can download.. manual here

 

Disconnect the speaker cables at the receiver and try again. Make sure you don't have a short in your cable or speaker.

Also, there is a self-diagnosis procedure in the manual that DodgyDave posted (see his link) - it should be able to tell you why the protection mode activated.

 

Everything is disconnected from the receiver. I can't use the self-diagnosis as display doesn't turn on.

 

Everything is disconnected from the receiver. I can't use the self-diagnosis as display doesn't turn on.

Yes, you can assume that is the case, or you can actually READ THE MANUAL!!! It tells you how to override the protection mode so you can keep the unit on and display the protection errors.

 

It doesn't work, there is no way to turn on the display.

 

See page22 to start in "cancel mode"

=============

Starting DIAG in the protection cancel mode
If the protection function works and causes hindrance to trouble diagnosis, cancel the protection function as described below, and it will be possible to enter the DIAG mode. (The protection functions other than the excess current detect function will be disabled.)
Press the “STANDBY/ON” key while simultaneously pressing those two keys indicated in the figure above. At this time, keep pressing those two keys for 3 sec- onds or longer.
In this mode, the [SLEEP] segment of the FL display of the main unit flashes to indicate that the mode is DIAG mode with the protection functions disabled.

==============

If this doesn't work, then you have an over current issue.

 

I tried it and it doesn't work. I am sure it's an over current issue as display doesn't even turn on, it doesn't even flash for a second or something.

 

This looks dangerously close to the same thing, id give it a quick look. It sounds like a common problem with Yamaha receivers. Not saying this is it but its worth a quick view.
http://www.youtube.com/watch?v=MwvjAtSr5t8
There is a part 1 as well.

 

Following your suggestion I checked some elements in the opening circuit. I found a problem:

Could this diode be a cause? Luckily I ordered a whole diode kit few months ago. Tomorrow I will solder find a replacement and solder it.

 

Replaced diode with 1N4148, still not fixed.

 

Protection circuit activates after few seconds. Relay clicks. Display does not work. What elements are likely to be damaged due to overheating? What should I test?

Image gallery:

http://imgur.com/a/BDQNI

Protection circuits are usually triggered by some kind of overload on the power supply. Really could be just about anything, but old electrolytics are always the first suspects.

 

Do you have the entire schematic for this unit? If so, could you possibly send it to me?

 

Here is a complete schematic:

http://elektrotanya.com/yamaha_av-receiver-rx-v361.pdf/download.html

(You need to click on "Get Manual")

Go to page 71 for schematic.