AVT50 Repair - Page 4 - diyAudio
Go Back   Home > Forums > Live Sound > Instruments and Amps

Instruments and Amps Everything that makes music, Especially including instrument amps.

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 23rd July 2012, 07:06 PM   #31
diyAudio Member
Join Date: Jun 2012
Could you be more specific?
  Reply With Quote
Old 23rd July 2012, 11:29 PM   #32
Enzo is offline Enzo  United States
diyAudio Member
Join Date: Sep 2004
Location: Lansing, Michigan
As it sits it makes loud hum. That is almost always either DC on the outpout or bad filter caps. DC will make the speaker cone move one direction and stay there. If it does that, TURN IT OFF. Disconnect the speaker. If it doesnlt do that, we move on.

Never connect a speaker to an amp until you knoiw it is not making DC on the output. Measure for DC voltage between the speaker wires while it is running. Should be none.

If no DC offset, then you have probably lost filtration. even if you replaced the caps, there may still be a bad connection to them or a cracked solder or circuit trace connetion.

The AVT50 uses the little power amp ICs TDA7293 on the very small circuit board mounted to the heat sink. Fan cooled. The little circuit board with IC I call a power module. It connects to the main board via cable. If there is DC on the output wires, than almost certainly this TDA7293 is bad.
  Reply With Quote
Old 24th July 2012, 01:05 AM   #33
diyAudio Member
Join Date: Jun 2012
Thanks. I will do some more checking.
  Reply With Quote
Old 12th December 2012, 11:09 PM   #34
diyAudio Member
Join Date: Oct 2012
I, I have an AVT 50, and it keeping blowing fuses when poweramp is connected. I changed BR, fuse (6 times) and Tda7293( twice) ..so, Im checking deeply and found that on LT+ it has 32V DC but 67V AC ??? Is it normal ?? ...On LT- is -32VDC with 0v AC.... Could you help to find out if it something wrong?? Any idea to solve this issue?

Last edited by moonmark; 12th December 2012 at 11:24 PM. Reason: grammar corrections
  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
Marshall AVT50 Mods JakeAC5253 Solid State 6 18th December 2014 01:46 AM
Marshall AVT50 Pops when Switching Channels morta Instruments and Amps 2 7th October 2010 05:13 AM
Marshall AVT50 Pops when Switching Channels morta Solid State 0 1st October 2010 01:50 AM
Getting better EQ on a Marshall AVT50 Fr_3_aK Instruments and Amps 15 3rd January 2009 11:01 AM
MARSHALL AVT50 mod. Vahagn Instruments and Amps 4 28th January 2006 07:52 PM

New To Site? Need Help?

All times are GMT. The time now is 01:09 AM.

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