20 Most Recent Sony STR-DB840 Receiver Questions & Answers

There are 4 blue relays in the unit that has solder points that will crack over time.
It´s fairly "easy" to re-solder them and viola, it´s OK again.

open the cover (unscrew and take of the hood) and locate the 4 blue relays. Unscrew and remove the bottom service plate and locate the soldering points for the 4 relays.
Each relay has 6 solderings, 4 in one "groop" and 2 in one "groop" look especially at the "2-groop" these are the ones most likely to crack over time ( for me 12 years or so).
Re- solder. Best of luck //Ronnie Stockholm

make sure sub is working .Power it up , remove sub RCA jacks from receiver .Gently tap on RCA with fingers.You should here a hum when touched .You can also try audio from TAPE REC OUT .If you dont get audio .Check setting at sub .If it working okay check setting at receiver and or sub level at receiver

There are bad solder connections on the circuit board inside the receiver, if you are handy with a soldering iron remove the top part of the case and trace the center channel speaker wires to the board, this will isolate the problem in the general area, chances are it is the center channel ic that need to be retouched.

That's for you to determine.

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 a root cause for intermittent shutdown.

SONY STR db840
No display:
broken trace on "Digital board" ,feeding 32v from "DC board" to "Display board"
solution: make new jumper btw. "CNS2" and "CNP4" on "Digital board"
Now display OK again : )

Turn on the subwoofer output. There is a configuration option for all the speakers: left, center, right, surround, and sub.

I am afraid not. That crackling is a component in one of the solid state amp circuits starting to fail. These are all soldered into the printed circuit board. This could be a difficult repair to find an intermittant component. Depending on how old the unit is and how much it cost will factor in on if you have it repaired or not. Rule of thumb is that if the unit is two to three years old and cost less the 200 to 300 bucks you should not invest more then 100 to 150 bucks into it. Good Luck

Hi David, do you want to connect the ST-D505 tuner to the TA-D505 amplifier? You just have to connect an audio cable of two RCA (red and white) from the audio output L and R of the tuner ST-D505 to the input of Tuner in the amplifier TA-D505 Remember to connect the FM antennas and the AM Antenna Loop on the ST-D505 tuner To listen to it, you have to select Tuner on the TA-D505 and enjoy the favorite radio stations I hope you have my comments Greetings Franco Dosil Hola David, quieres conectar el sintonizador ST-D505 al amplificador TA-D505? Simplemente tienes que conectar un cable de audio de dos RCA(rojo y blanco) desde la salida de audio L y R del sintonizador ST-D505 a la entrada de Tuner en el amplificador TA-D505 Recuerda conectar las antenas de FM y la Loop Antena de AM en el sintonizador ST-D505 Para poder escucharlo, tienes que seleccionar Tuner en el TA-D505 y disfrutaras de las estaciones de radio preferidas Espero que te sirvan mis comentarios Saludos Franco Dosil https://elektrotanya.com/sony_lbt-d505_d505cd_d505cdm_d505m.pdf/download.html

troubleshoot the issue: Reset the CD Changer: Turn off the CD player. Press the CLEAR button. Simultaneously, press and hold down the POWER button on the CD player for 60 seconds. If this doesn't resolve the issue, proceed to the next step. Check for Error Messages: If you encounter difficulty playing a disc and receive any of the following error messages, there may be an incorrect setting or a problem with the disc: NO DISC DISC ERROR CD ERROR TOC ERROR Refer to the instructions supplied with your CD player to verify model-specific information and troubleshoot the issue. Internal Component Repair: If the display issue persists, it might be related to an internal component that requires repair.

Troubleshoot this issue. Here are some steps you can follow: Check Speaker Connections: Ensure that the rear surround speakers are properly connected to the Audio/Video (A/V) receiver. If applicable to your model, verify that the A/B speaker selector is set correctly. If the speakers are connected to the A speaker connection, the selector must be set to the A position. Test Tone Operation: Perform a test tone operation to check if the speakers are functioning correctly. Increase the rear speaker volume or adjust the surround speaker settings to the maximum level. Speaker Size Settings: Try selecting a different size (small or large) for the rear surround speakers in the menu. Surround Sound Mode: Verify that the A/V receiver is set to a surround sound mode. For Dolby ProLogic surround sound, ensure that the center-channel mode is set to NORMAL or WIDE. If your source is a DVD or Blu-ray Disc player, check that surround sound is enabled in the player's menu. The audio being received must be multi-channel. Different Surround Sound Mode: Try setting the A/V receiver to a different surround sound mode. Source Content: Verify that the source you are playing is encoded in surround sound. Note that during periods of mainly dialog, most of the sound may come from the center speaker only, with audio coming out of the rear speakers when there is background or ambient noise. Factory Reset: Reset the unit back to factory default settings (consult your operating instructions for model-specific steps). If applicable, follow the steps for calibrating the appropriate settings automatically after connecting the calibration microphone device. Speaker Wires and Replacement: Check and replace the speaker wires if necessary. Consider connecting a different pair of speakers to see if the issue persists. If you've tried these steps and the problem remains unresolved, I recommend seeking professional service.

steps to troubleshoot and potentially repair them: Troubleshooting Low Sound or No Audio from Rear Surround Sound Speakers: If you're facing audio problems, especially with the rear surround sound speakers, consider checking the following: Ensure that all speaker connections are secure and properly plugged in. Verify that the speaker wires are not damaged or frayed. Check the speaker settings in the system menu to ensure correct configuration. Inspect the speaker impedance and compatibility with the system. If you're using wireless speakers, check their power supply and connectivity. Refer to the operating instructions manual for specific troubleshooting steps. Flexible Circuit Board Repairing: If the issue is related to internal components, you might need professional repair. However, if you're comfortable with electronics, consider these precautions: Keep the soldering iron temperature around 270°C during repairs. Avoid touching the soldering iron on the same conductor of the circuit board more than three times. Be gentle when soldering or unsoldering to prevent damage to the conductor. Important Notice: To prevent fire or shock hazard, avoid exposing the unit to rain or moisture. Do not open the cabinet; refer servicing to qualified personnel. Avoid installing the appliance in confined spaces like bookcases or built-in cabinets.

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