20 Most Recent Sony STR-DB940 Receiver Questions & Answers

There are several things that can be the cause of this. One of them is the use of a super capacitor (think battery) that saves settings in the memory. When this fails the unit wont start.

Hello did you find any solution ?I have exactly the sams issue with the harmony one and the STR-DB940 and I don't find the solution till now

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.

I dont think that it is the case...the 5+1 is usually connected 2 by 2 central..and so on ...In your case either you selected stereo out in the menu ..and in this case you can not have all the channels working ..or ..the amplifier 's chip for that channel is dead..and in this case you have to change it ..The action involve opening it ...identify the line chip ..and change it ..and if you do not have the instruments to measure it ..you have to get proper help ..
BUT , first try in the settings ..and also check the input signal ..or cables ..specially if the input is divided on 3 like I said ...it is enough an unplugged cable ..

• Try this on your rceiver to see if it corrects your problem .If not make sure rear speakers are activated and properly connected
• Sound Field Clear Mode
  The preset sound field is cleared when this mode is activated. Use
  this mode before returning the product to clients upon completion
  of repair.
  Procedure:
  1. While depressing the [MODE +] button, press the power `/1
  button to turn on the main power. The message S.F Initialize
  appears and initialization is performed.
  
• 
  

hello, try testing the diodes first make sure you desolder 1 end and lift away from the board this will make sure you get a proper reading on the multimeter if theses ok check transistor next take them out of the board if ok then resistor same again out of the board . when testing capacitors make sure there not bulged it would be better if you can get an esr meter for testing capacitors good luck

regards
shaun

if its a 5.1 channel home theater,it means you have to hook up the subwoofer or maybe a center speaker to its terminal to have them all working. 2 front speaker,2 rear speaker and 1 center speaker or subwoofer =5 and amplifier is 1 so it is a 5.1 channel.hope this help..

I'm guessing these are separate issues.

Has either one ever worked and stopped suddenly?

From the manual:
"No sound or only a very low level sound is heard from the rear speakers.
>>> Make sure the sound field function is on (press SOUND FIELD - MODE).
>>> Select a sound field containing the word "cinema" or "virtual" (see page 33-35).
>>> Adjust the speaker volume (see page 72).
>>> Make sure the rear speaker size parameter is set to either SMALL or LARGE (see page 20)."

Be advised that using any Tape Monitor loop (that's what the MD/DAT is) disables any digital sources. Not that that would explain the rear speaker failure. Analog sources can still be processed into various surround modes.

Any Tape Monitor use requires at least a live INPUT to hear anything.

Whats the rating on the Plasma? How many watts at 4 ohms? If the plasma is rated 100 w at 8 ohm... hanging a 3.4 ohm load would put a lot of strain on the plasma's output amp. At 3.4 ohm the amp would be trying to delive close to 200 watts at full power. But it depends on how hot you normally run the volumn. Remember an amplifier output is AC volts. 1 ohm of resistance is close to a dead short. The amplifier would have to work its *** off to supply that type of power and would probably burn the output op-amps. If the outputs burn & it pumps any DC current through the speaker wire..the speakers would be toast...if not catch on fire. Try to keep the speaker load at or very cloe to the plasma's output load rating. Also if the plasma doesn't state it will handle loads down to 2 ohms...It probably won't.
Gene

I have the same problem. Over the night the sound disappeared. It happens on all the inputs(analog/digital) and with speakers/headphones. The digital signal is correctly detected and all the 'clicks' are like before when turning the amp on. Switching to direct mode does not help. Is there schematics available somewhere? I suppose it's some output related soldering which has come loose. If only I knew where to look, or point a local service guy to right direction...

no adjustments in that unit for timing

Check if you're using the digital cables like optical cable to get the audio from the receiver. If yes, please select the Input mode to AUTO by pressing the mode button repeatedly. If you're using a analog cables, please try to change the sound field and check. Press the A.F.D button repeatedly to change the sound field and try. You can also try connecting a different audio source like Cable box, dvd player and check the issue.
If the issue persists, please reset the receiver. To reset the Receiver, turn OFF the unit and press n hold the MODE + button and Power button till S.F Initialize appears. If the issue still persists, you may be having 90 days warranty after the date of repair or original warranty which ever is longer. Contact sony to resolve the issue.

i need a little more detail to help you out, one issue it could be is that you have your reciever set to optical audio when you dont have an optical cable for it, if thats not it, re check your connections