Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Chip Amps Amplifiers based on integrated circuits

Onkyo amplifier A-RV401 - output signal to speakers cuts intermittently
Onkyo amplifier A-RV401 - output signal to speakers cuts intermittently
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Thread Tools Search this Thread
Old 26th May 2010, 03:35 AM   #1
gerolo is offline gerolo
diyAudio Member
Join Date: May 2010
Default Onkyo amplifier A-RV401 - output signal to speakers cuts intermittently

Hi everyone,

I'm kind of a newbie on troubleshooting electronics issues, so any pointers on the following will be greatly appreciated: I have an integrated Onkyo amplifier, model A-RV401 (bought in 1994). For the last few years, I've noticed that the audio output to the speakers is cut intermittently (mostly on the right channel), when listening to sources connected to any of the A/V inputs at low input levels.

According to what I've observed, the problem is not related to the volume knob or bad speaker connection. A momentary workaround is to quickly turn the volume up and then back to the previous position, but after a few secs/minutes sound starts to get scratchy again. Today I plugged my MP3 player to the front A/V input, and started getting scratchy sound when turning the volume of the MP3 player all the way up, and the amp volume to a 1/4 of its total approx. However, I found out that even if I turn the amp volume up a little and then turn the MP3 player volume down, the problem still shows up - so it's kind of related to the level of the signal that is fed to the speakers, rather than to the position of the volume knob.

I've read several posts concerning faulty capacitors in old amps, and how they affect performance. I've got an schematic of my amp's circuit board, but I'd appreciate some pointers on where to start checking for any faulty components.

Thanks in advance for your help!!!
  Reply With Quote
Old 26th May 2010, 05:34 AM   #2
tangmonster is offline tangmonster  South Africa
diyAudio Member
tangmonster's Avatar
Join Date: Jul 2007
Location: Cape Town
I would suggest posting the circuit diagram

Also , mostly capacitor problems only happens in MUCH older amplifiers than yours.

What i have found in a few 90's and up amps is that they use 78xx and 79xx chips in a few places and that i have had them become intermitted due to very poorly designed too small heatinks.

One time I thought it was a 7805 that had a problem and then it turned out to be a very small bridge rectifier before it.

So like always , test all the power supply voltages on the 78xx and 79xx pins and any other power sources. Since it's only one channel I might be on the wrong path..

And it might be an opamp...
  Reply With Quote
Old 26th May 2010, 02:26 PM   #3
east electronics is offline east electronics  Greece
diyAudio Member
east electronics's Avatar
Join Date: Jan 2006
Location: Athens GREECE
it could be a number of things ...one that is easy to trace down is the output protection relay if exist .... keep the cover open watch out for dngerous voltage and use a plastic pen to tap over the relay while playing music

by the same logicand always with aplastic part and always carefull you may tip and tap here and there over the pcb to locate a loose connection or bad soldering

i also agree to capacitors .... they seem quiet yound to be replaced ... but look also for the obvious ....fluids arround them , salted corosion of any form , signs of thermal stress here and there

post pictures ...post a schematic if its available

regards sakis
  Reply With Quote
Old 12th October 2010, 06:44 PM   #4
schepbo is offline schepbo  Netherlands
diyAudio Member
Join Date: Oct 2010
i have the exact same problem, same amp
  Reply With Quote
Old 12th October 2010, 08:03 PM   #5
stoc005 is offline stoc005  United States
diyAudio Member
stoc005's Avatar
Join Date: Feb 2007
Location: Midwest in the USA
More than likely it is the speaker protection relay that is dirty. If it has them, tap each one and see if the sound returns or is intermittent. Clean them with contact cleaner and fine emery paper, 600 or so grit. If sealed, be prepared to replace them.
  Reply With Quote


Onkyo amplifier A-RV401 - output signal to speakers cuts intermittentlyHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Onkyo speakers I just got. srinath Multi-Way 7 18th February 2010 12:47 PM
onkyo dx7711 tube output costa23 Digital Source 0 2nd February 2010 04:04 AM
onkyo T866 amplifier moxie Vendor's Bazaar 0 15th April 2008 11:25 PM
Has anyone modified Onkyo HTiB speakers? Hoss27 Multi-Way 1 13th December 2006 04:55 PM
onkyo integar A-9711 amplifier vaci Solid State 7 26th August 2005 09:05 AM

New To Site? Need Help?

All times are GMT. The time now is 02:11 PM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio