20 Most Recent Sony STR-DE715 Receiver Questions & Answers

Does the rest of the receiver work? Do you get audio output? If not, it could be the main power transformer. There is a thermal fuse buried in the core that if this opens, it will cause the unit to not power up completely.

Might be short circuit protection or over load protection activated. Contact any service technician, to confirm what the reason is. If you wish to get some details; check the site linked here. Viewing it in "Mosaic" or "Magazine" will make surf easy. Pull up older posts. Surf the site with patience. Do a search by type in the brand name of your device at its search box and press "Enter". http://electronicshelponline.blogspot.com/

hi,
First of all remove all the speaker connections from the amplifier. After that power the amplifier and check the protect show or not . if not, then any of the speaker is damaged. If then also it shows protect you have to check the amplifiers hardware.

AV receivers shows protect mode , when there is a hardware fault in side it. Its a warning that some thing is wrong.
Normally AV receivers show this when any of the output amplifier have some problem. there are five amplifiers in this AV receiver. May occur when the output diver transistors of any of the amplifier become shorted. if the output transistor get shorted this will lead to flow of current through the speakers. To prevent this there is a protection circuit for each channels. One combined output of this protection circuit is connected to the system control. when the any of the output amplifier fails, the protection circuit detects it and switch of the speaker and sent data to the system control. when the system control get this data it will give a warning to the customer through display that PROTECT.
You have to check the amplifier.
For that you need digital multimeter,soledring iron screwdrivers etc
Open the amplifier , then power it on. connect the negative terminal of the multimeter any where in the chase( metal body of the amplifer). then connect the positive terminal to all the output transistors emitter pin one by one . the voltage should be bellow 0.5V. If any of the emitter of the transistor shows voltage more than 0.5V., then that amplifier stage is faulty. Remove the transistors and check it. if it is shot then replace with a new one.
after replacing the transistors do not power up the amplifier directly from the main. You have to put a bulb of 60 watts in serial.
You can do this easily remove the mains fuse. put the bulb in a holder. now you have to wire from the holder. connect one of it to the one end of the fuse holder and the other wire to the other end of the fuse holder. Why using a bulb is, if there is any further problem in the amplifier stage on which the transistors replaced, there is a possibility of the new transistor get damage. if we use a bulb in serial with its mains supply ,when any overload in the amplifier occur the bulb will drop the current, by lighting itself.
After connecting the bulb in serious power on the amplifier. watch the bulb. It should light for one or two second and go dim . if so check the display, is there is protect mode is on or not . if not and come back to normal operation ,then remove the power , remove the bulb insert fuse and check
connect the power and check.
If the bulb shows bright light then there is some component also faulty in the same amplifier. after removing the power you have to check again the amplifier stage of which the transistor is replaced, for any other faulty components.
I have the service manual for the same. if you need the same will sent it to you. For that i need your email id. As it is a large pdf file can't sent through fixya.
ok

Protector appears on the screen

The audio amplifier IC are damaged and need to be replaced

Hi...
Is it LOUD when you first turn it on?
Are the speakers firmly connected at BOTH ends?
If that's all OK then one or both of the output modules in the power amp have failed.
Parts are available

If the output are good, Check for a bad/loose ground. Check the solder near the input jacks, and tighten any and all ground screws that hold the circuit boards to the chassis. It could also be a bad transistor in the protection circuit.

I have the same problem, i also have a STR-DE715. I have two thunder acoustic speakers and two 12in. punch subs. Now when i only play the subs i can go max volume, no problem, great bass the whole deal. Then when i play the thunder speakers i cant even go half way without the receiver shutting off and saying "protector" on the screen(both the speakers are 120 watt). From personal experience i think it could be the speakers youre using, either the receiver is giving too much juice and its preventing the speakers from blowing or the speakers need more power and the receiver cant give it. So a new set of speaker might be what you need. The receiver is 280 watts so something in that zone should work out. Also try turning off the sound field if you're using more than two speakers for the front output (i read this in the manual, you can pull up the users manual on www.manualshark.org and see if you can find something i might've missed) it supposed tp help it in one way or another. E-mail me at [email protected] and tell me if your problem was fixed or not. Im pretty curious myself to find a solution to this problem. hope this helps!