Help Troubleshooting - 3pc Speakers - Storm blew something!?! - diyAudio
Go Back   Home > Forums > Amplifiers > Chip Amps
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Chip Amps Amplifiers based on integrated circuits

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 13th October 2009, 11:57 PM   #1
diyAudio Member
Join Date: Oct 2009
Default Help Troubleshooting - 3pc Speakers - Storm blew something!?!

Hi all, i'm new, not sure exactly where to post this.
I have a 3pc speaker, two tweets and a sub, Harman Kardon mod#395. There was a storm recently and now there is no sound output.

I've tested the speakers but i'm not too familiar with testing electrical components, and there are so many I was wondering if anyone knew the easiest way to test the board? There are two LM324 op amps and a TDA 7375 power amp. Fuse is fine, speakers work, power is on! Just no sound... any suggestions or more info needed? I assume there are a few things that are always checked first after a storm, but i'm new to this so that info would save me some time.

Thanks for any help!
  Reply With Quote
Old 14th October 2009, 01:37 AM   #2
diyAudio Member
raypalmer's Avatar
Join Date: Dec 2008
Location: Burlington
Checking multiple sources in multiple inputs....
Wherever you go there you are.
  Reply With Quote
Old 16th October 2009, 10:13 PM   #3
gfiandy is offline gfiandy  United Kingdom
diyAudio Member
gfiandy's Avatar
Join Date: Jul 2003
Location: Cambridge UK
First thing to check are the power rails to all the components. Download the data sheets for the parts. Identify the power rails and the range of voltages they will work over. Use a multimeter to see if the right voltages are present on the power rails. If you don't have a multimeter go buy a cheap one, you can get them for £5 and you won't make any progress without one.

If the right voltages are not present try to work out where the voltage rail comes from by following the track back to the regulator for the rail. Then test to see if a voltage is present on the input to the regulator, if it is and there is no voltage on the output you have found your problem. Given that you have no sound at all it is most likely to be a system wide problem like a power rail.

If its not a power rail you will need to start tracking the signal through the system this is quite complex and would be difficult especially for a novice without a circuit diagram. But you could give it a go. Find a loud CD with as constant a sound as possible (A sinewave signal CD is ideal if you have one, sometimes the audio mags give these away) heavy rock is probably a good starting place. Set the multimeter to AC and measure the signal at the output of the source. Then try to track it from the input conector through parts in the circuit till it disapears to identify the part that is faulty. Note inverting opamp designs do not apear to have any input signal if you measure it at the input pin because it is a virtual earth, however if the signal is present on the output you can be happy that it is working.

  Reply With Quote
Old 19th October 2009, 02:28 PM   #4
diyAudio Member
Join Date: Oct 2009
That's exactly the response I needed, thanks so much!
  Reply With Quote


Hide 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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Gale storm 8 delphiplasma Subwoofers 12 30th March 2011 12:48 PM
Need help troubleshooting whine in speakers roger2 Car Audio 5 19th May 2009 04:22 PM
Massive Magnetic Solar storm KBK The Lounge 11 31st December 2006 07:00 PM
Blew my speakers with a guitar - can I fix them. mga Multi-Way 26 6th August 2006 09:29 AM
Computer speakers blew out! JiggaD369 Multi-Way 4 30th April 2006 05:20 AM

New To Site? Need Help?

All times are GMT. The time now is 01:44 AM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2