41hz and Amp6b Fault - diyAudio
Go Back   Home > Forums > Amplifiers > Class D

Class D Switching Power Amplifiers and Power D/A conversion

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
Reply
 
Thread Tools Search this Thread
Old 18th March 2013, 04:03 PM   #1
Svampan is offline Svampan  Denmark
diyAudio Member
 
Join Date: Feb 2013
Location: Copenhagen
Default Amp6b, fault in output 1

Hello Diy'ers

I've been trying to make a post on the 41hz forum, but after using 3 different email addresses, I don't get an activation mail. So I'll post my problem here instead:
__________
I've been working the whole weekend to assemble and troubleshoot my first amp 6b. I've been very careful in the assembly, and thought I had some pretty darn good shiny concave solders.

At first the amp would only play on channel 2. I then went through all the solders again, and cleaned the board, only to measure 12v on the cathode of d6 -, and the amp not playing at all. (perhaps the protection of the chip kicks in when rail voltage is coming through a faulty D10?) I've been through various troubleshooting threads, but nothing seems to help. Here's some data that may help in finding the problem:

5.1v over C2
0v over R7
8.2v over c5

2.2v to ground after input caps

12v to gnd on - side of L1, 0.1v on + side
5.9v to gnd on - side of L2, 5.9v on + side

5.8v to gnd on output 2 +, 5.9v for -
0.2v to gnd on output 1 +, 0.1v for -

Measure on cathode to gnd:
5.9v on D8
5.9v on D7
12v on D6
0.2v on D5


I've used this method by Scatchy to check the input paths, and the input resistors seemed ok. over the inductors it read 2 ohm on L2 + & -, and 2 ohm on L1 + and unable to measure on -.

I believe the problem is a fried chip, due to the voltage difference (possibly a short-circuit around pin 26), and possibly a bad solder on L1. The measured rail voltage on output 1 suggest a fried diode, how could this be?

Hope you guys can help me out, anything would be much appreciated!

Here are some pics of the board:

Click the image to open in full size.
Click the image to open in full size.

Last edited by Svampan; 18th March 2013 at 05:08 PM.
  Reply With Quote
Old 19th March 2013, 10:50 PM   #2
diyAudio Member
 
Join Date: Nov 2009
Location: Sydney
I can see a big blob on the left inductor, prime candidate.
You may need some flux to convince it to flow under it.
  Reply With Quote

Reply


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
arjenhelder Vs 41HZ JammyBStard Class D 10 3rd February 2010 02:17 AM
41hz Amp 4 ebag4 Class D 6 19th November 2006 04:07 PM
New kits from 41hz filholder Class D 29 27th August 2006 12:45 AM
Help with 41hz AMP 3 bcrescen Solid State 0 13th August 2006 07:09 PM
41Hz AMP3 Pano Class D 12 25th April 2005 09:07 PM


New To Site? Need Help?

All times are GMT. The time now is 01:36 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2