Question about Audio Players & Recorders

1 Answer

Stereo Amplifier fades out. My Sansui dolby pro

Stereo Amplifier fades out. My Sansui RZ-2200AV dolby pro logic surround sound amplifier has stopped working properly. Sometimes when I turn it on, it will work for a few seconds before the volume fades out slowly with a fuzzy sound as if it's losing power. Sometimes it just won't work at all. I've tried different inputs, even using the built in FM receiver, all sources respond the same way.

Posted by on

  • 4 more comments 
  • contact556 Dec 14, 2009

    Why thankyou :) I pride myself on my troubleshooting abilities! The sound comes on with a slight delay with power on. I tried it again yesterday and it was fine for about 15 minutes then there was a slight pop noise and it faded out quite quickly (too quick for me to notice if there was a fizzle noise).

    I just tried it again after 24 hours rest, and it was no good. This time I used an iPod to RCA connector. The sound was immediately very weak and "fizzy" like I was half-tuned into a very very weak AM radio station. Yes it is both Left and Right (that's all I've got connected at the moment). Thanks for your help.

  • contact556 Dec 26, 2009

    OK, great tips - thanks.
    It is not intermittent anymore.

    I've tried using headphones - same issue.

    I've tried using the test tone and cannot hear it. So it is affected too. (The test tone is a kind of white noise anyway, so it'd be hard to tell in the tiny, faint, crackly noise I can hear in the speakers).

    I've tried monitoring with tape out, and lo and behold - I can hear both FM radio clearly and also playing an iPod through the Amplifier. So, that seems to indicate something in the power amplification circuitry, correct?

    Lastly, I've fiddled with balance and treble and bass, as well as all surround settings and there is no change, so I guess that rules out a dodgy switch or pot too?

    Thanks so much for your help so far!

  • contact556 Dec 26, 2009

    Ah, already disconnected all speakers. Sorry, I forgot to mention I did that. Just retried connecting only one speaker at a time, and also swapping left with right just to be doubly sure.

    There is an overload indicator, but it is not on.

    To clarify regarding the 'pop'. I had never heard the pop previously when the amp had died out before, or since. Just that one time. But since that one time, the very low crackly volume has been an constant issue, rather than intermittent.

  • contact556 Dec 26, 2009

    Awesome. Thanks for your help. I'm going to crack it open myself to see if it's obvious. Then hopefully save myself some cash!

    You've been a great help. Thanks again.

  • contact556 Dec 31, 2009

    Interesting update:
    Opened it up and had a look. No caps had that obvious bulging look, however there was one on the power source circuit board that had dried up brown stuff on one side and onto the board - however I understand this is probably more likely to be old glue.

    I wiggled it to check and it did seem to move a little bit more than others.
    A little while later I tried the amp and it worked again for a bit.
    However the next time it didn't. But here's the interesting bit: when I pressed the power button in (which is a physical button that has a mechanical connection to the actual button back on the power source circuit board), to turn the amp off - it suddenly sprang to life again. To me, that sounds like there's maybe a cracked solder joint on that board, does that sound reasonable?

  • contact556 Jan 04, 2010

    Well...Final update: I finally found the problem; a couple of cracked solder joints on a couple of resistors on the power supply circuit board! Almost impossible to see, but I could see a little heat discolouration in that area and pushing various areas with a pencil - tracked it down. Reflowed the solder and added a touch more and it's all good now! Since then I've found out I can't run audio direct to it while watching my new LCD anyway because of the dreaded input lag with HD screens! Argh!.

    I want to thank you for your excellent help and patience in narrowing this issue down. You gave me the confidence to do it myself. Cheers.



1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.

    Brigadier General:

    An expert that has over 10,000 points.

  • Master
  • 8,546 Answers

No that's how to describe a problem, folks - with details. Using internal FM as the source is always the preferred way of troubleshooting system-wide receiver audio problems (no cables or setting in the way).

Does the sound come on immediately with power and then fade or is there a small delay while the electronics stabilize, a click and then sound that fades?

The fizzle probably means something is rapidly overheating or a capacitor is malfunctioning. If both channels do it, I'd suspect a common power supply problem. Can't help much more than that.

Posted on Dec 12, 2009

Testimonial: "Great help so far! Clearly written, clear concepts for isolating the problem, and very personable interaction. Highly recommended expert!"

  • 2 more comments 
  • David Dunn
    David Dunn Dec 15, 2009

    The worst problems are the intermittent ones.

    Continue monitoring for some sort of pattern. We know the effect, now we need to find a cause.

    That it stays up for some time might help. The slight pop might be the result or the cause of an impulse kicking something over the razor edge on which it teeters.

    Okay, we're still on the track of a component or internal signal path malfunctioning over some random time. It's now starting to sound like a connection or circuit slowly failing.

    Staying with internal FM, manipulate controls and switches on the amp.

    Do you have a tape deck? Connect it to the Tape Out and monitor the level meters when it fails. If the sound drops to the Tape Out jacks that lets out the amplification circuitry and narrows it down to a signal path problem. THAT would cut the problem diagnosis in half.

    If the signal is still is still present but not audible at the speakers it's in the amplification path but still possibly in tone or balance controls.

    I see online there's a Test Tone. Set that up when the unit is working and determine how far it goes through the receiver. You could quickly substitute it as the source when the unit fails. I suspect it would bypass the internal tone controls so its audibility might help to further isolate the failure.

  • David Dunn
    David Dunn Dec 26, 2009

    In reviewing what we have so far I just noticed you mentioned a pop (Dec 14) preceding the loss of volume. I'm not familiar with how this unit reacts when it goes into speaker protection mode or if it has an indicator to tell you it's active. Most just crowbar the output by dropping a relay (click), perhaps yours produces a fizzle and goes silent until the perceived problem clears up.

    When you normally power up the receiver did it have an audible click a few moments afterward, indicating a protection relay energizing to enable the amps? If so, does it still click even in failure mode?

    Internal problems would most likely be caused by excessive current or heat. I doubt it's heat because you now have a solid problem that apparently appears as soon as you power it on.

    Let's eliminate speaker shorts as a problem. If the problem is solid turn it on, adjust the volume control to a low-normal setting (just in case it comes back to life) and start disconnecting or disabling speaker sets. If the amp suddenly comes back we have an external problem like a shorted speaker wire.

  • David Dunn
    David Dunn Dec 26, 2009

    OK. I think surgery is needed now. You probably heard a power capacitor give up the ghost.

    For diagnostic purposes and to satisfy your own curiosity (you're on the scent now), you could go inside and look for a blown component. Big caps typically look like little batteries.

    Unplug the unit. NEVER touch a capacitor with your bare hands before discharging it by shorting the contacts.

    They don't always exhibit external evidence of having blown. A trip to the shop would be the next step since the problem is solid now. They should find it quickly.

  • David Dunn
    David Dunn Dec 31, 2009

    Tally Ho!

    I think you are HOT on the trail, however, tread lightly around suspicious power connections, do most of your physical contact troubleshooting with power off, being mindful of the dangers not only to you but to the components should you suddenly experience rapid make/break of a contact.

    That brown dried up stuff could be electrolyte from a blown cap. I'd look a bit closer at that, too.



1 Suggested Answer

  • 2 Answers


Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

Would I be able to connect an external Technics SH-8036 Stereo Graphic Equalizer to my Technics SA-500 receiver?

Yes, it is hooked up using the (cassette) tape inputs and outputs. Use the tape monitor switch on the receiver to switch the EQ in or out.

Feb 11, 2016 | Panasonic Technics Sa-dx930 A/v Stereo...

1 Answer

All the speaker outlets seem to work fine, except the fronts, all will work, but if i plug the fronts in, all the sound then tends to just fade away, and then i have nothing, no sound. i can't figure...

I would:
1- First make sure you are properly testing using a reliable source, such as a CD Player or itunes. 2- Make sure the Listening Preset is not on Dolby Pro Logic. Make sure it is on Stereo mode and see if the problem persists.
What usually happens is that when listening to 2ch (Left and Right) Audio such as Television or Music and Dolby Pro Logic is on as a preset, Dolby Pro Logic analyzes both Stereo tracks, tries to detect the voices (center channel), ambient sounds (surround and fronts) and processes the signals into a 5.1 or 6.1 System. You tend to get a fading effect when Dolby Pro Logic is selected and listening to an old VHS, DVD or even music.
To remove a preset, make sure you select the Stereo button at the bottom left of the remote to pan through the options.
Hope this helps

Jul 21, 2011 | Harman Kardon AVR 230 6.1 Channels...

1 Answer

How do I get the C5 Subwoofer to activate?

If subwoofer is inactive now, the sound preference settings you set now is wrong.

Before using the remote control for the following
* Set the remote control mode selector to AUDIO

** There are exceptions in the operation mentioned
above. In such a case, follow each instruction

Dolby Pro Logic II*1

# Dolby Pro Logic II has a newly developed multichannel playback

format to decode all 2 channel sources - stereo source and Dolby

Surround encoded source - into a 5.1 channel.

Dolby Pro Logic II has two modes - Movie mode and Music

# Pro Logic II Movie (MOVIE)
Suitable for reproduction of Dolby Surround encoded sources

# Pro Logic II Music (MUSIC)
Suitable for reproduction of any 2 channel stereo music sources

# Dolby Digital*1

Used to reproduce multichannel soundtracks of the software
encoded with Dolby Digital

# DTS Digital Surround*2

Used to reproduce multichannel soundtracks of the software

encoded with DTS Digital Surround. DTS Digital Surround (DTS) is another discrete multichannel
digital audio format available on CD and DVD software

Jun 19, 2011 | JVC TH-C5 System

1 Answer

Whent I connet my android to my samsung HTC55 using the aux 2, just one speaker work, that is correct? is there a way to connect my android and all my speakers work

Your Android phone can only output in mono or stereo, but it does not have a surround sound decoder, so it cannot output natively to a 5.1 surround sound system. However, your HTC550 has a Surround Sound Mode called Dolby Pro Logic II, which will simulate 5.1 sound from any stereo input. Try activating Dolby Pro Logic II mode on your receiver to get surround sound on your Android phone.

Apr 28, 2011 | Samsung HTC550 Theater System

2 Answers

The audio keeps going in and out and cuts off. Also I have other devices going into aux in but it doesn't show 5.1 surround it only shows the front L, Front R, and CT speakers in stereo. I want everything...

If you are playing a source that is Stereo such as FM Radio or a CD the sound will not use all 5.1 speakers unless you enable the correct Surround Mode. On the remote there is a button on the lower right of the remote that says SURROUND. You can toggle through the various surround modes with this button the mode you want is Dolby Pro Logic The Pro Logic mode uses the built-in circuit to steer the Left, Center, Right and Mono Surround channel audio signals and uses all five speakers to play both stereo and Dolby Pro Logic program source, such as TV and VCR. You can use this mode with any stereo program source (such as VCR/TV) to enjoy multi-channel sound experience.

Mar 02, 2011 | RCA RTD317W Theater System

1 Answer

Not getting true surround sound

The only way to get Dolby 5.1 audio out of the Xbox will be via fiber optic cable from the Xbox to a Dolby Digital amplifier - which will output a decoded 5.1 signal to a 6 channel amplifier and 5 speakers and one sub-woofer. I doubt the Logitech speaker system has a Dolby 5.1 decoder built in with the amplifier for under $100, but I can't say for sure. If the Logitech has a an optical (or TOSLink) input, connect it to the Xbox and follow the instructions below.

To configure your audio settings, follow these steps:
  1. Start the Xbox 360 console without a disc in the disc tray.
  2. In the System section of the Xbox Dashboard, select Console Settings.
  3. In the Console Settings area, select Audio.
  4. In the Audio Settings area, configure settings for analog output or digital output:
    • Analog output settings:
      • Dolby Pro Logic II: Select this setting for stereo systems or Dolby Pro Logic II-compatible systems.
      • Mono: Select this setting for systems that do not support stereo output. Note If you have connected to Xbox LIVE and downloaded any AutoUpdates, the Mono option will not be available.
    • Digital output settings:
      • Digital Stereo: Select this setting to use digital stereo output.
      • Dolby Digital 5.1: Select this setting to use Dolby Digital output.
      • Enable WMA Pro: Select this setting to enable WMA Pro pass-through if your receiver supports the WMA Pro format.
Note You must use one of the following cables to support digital output:
  • Xbox 360 Component HD AV Cable
  • VGA HD AV cable
  • S-video AV cable
  • Advanced SCART AV cable
  • Japanese HDAV D-connector AV cable
Additional info:

Sep 28, 2009 | Audio Players & Recorders

2 Answers


In the PS3 menu, open Settings > Video Settings > BD/DVD Audio Output Format (HDMI) or (Optical Digital) depending on which one you are using. Set the type to to Bitstream (Linear PCM does not send the DD stream through).

Oct 23, 2008 | Sony Playstation 3 (PS3) Console

1 Answer


are you trying to use the surround sound for movies or music ? , ive got the dvd version of this system (sc-dv290) and ive noticed the surround sound tends not to perform well with music , but sounds great with movies. i think its because the movies have dolby digital and music does not. The dolby pro logic in my opinion doesnt really make that much of a difference in sound unless the sound is cranked up past 44db on the amplifier. the only cables you need are the ones that are attached to the surround sound speakers and they cannot be removed so it cant be the wiring . I reckon you have a 1 - faulty system 2 - listening to music 3 - maybe not pressing the pro logic button on the sound processor. Hope this helps

Sep 11, 2008 | Technics SC-DV290 System

1 Answer


Straight from the product's manual...

Amplifier section
Power Output-
[Stereo Mode]
125 watts per channel

[Dolby Pro Logic Mode]
120 watts per channel

Rear (Surround)
60 watts per channel

120 watts

Click HERE for the manual.

There you have it.


Nov 10, 2007 | Aiwa AV-X220

Not finding what you are looking for?
Audio Players & Recorders Logo

Related Topics:

980 people viewed this question

Ask a Question

Usually answered in minutes!

Top Audio Players & Recorders Experts


Level 3 Expert

5683 Answers

The Knight
The Knight

Level 3 Expert

76036 Answers

Steve Allison
Steve Allison

Level 3 Expert

5569 Answers

Are you an Audio Player and Recorder Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides