MTX Thunder 280 Inverter Issue ! - diyAudio
Go Back   Home > Forums > General Interest > Car Audio

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 25th January 2013, 10:53 PM   #1
diyAudio Member
 
Join Date: Jan 2013
Default MTX Thunder 280 Inverter Issue !

I am trying to fix this amp for a friend, so I do not know the history of it.
It had the two resistors that feed the gates of the inverter missing, with two burnt marks. I have replaced the two MOSFETs (IRFZ11 50A 60V) with two NDP710A 42A 100V). I know this is not a direct replacement, but I had these from a previous project. There is a small thermistor that I do not know the resistance of ?
I would greatly appreciate someone measuring their thermistor at 70 Deg for calibration and letting me know how many Ohms it should read. I have checked the two FEP16CT diodes, they are fine.
Does the LM339 send a start pulse for the inverter to start or does the inverter start automatically, once 12 VDC is applied to the amp?

Thank you in advance for any help.

All the very best, Mad Yank !
  Reply With Quote
Old 29th January 2013, 02:14 AM   #2
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
I'm not sure about this amp but many of the MTX amps have constant power feeding the LM339 and the TL494. Pin 4 of the 494 is used to enable/disable the power supply. If you want to try to disable the protection circuit, find a small PNP transistor that has it's emitter connected to pin 14 of the 494 and its collector connected to pin 4 of the 494. Remove that transistor. This will disable the protection circuit so you must take all precautions listed on the basic repair page to prevent damaging the amp further.

With the protection circuit disabled, does the amp produce clean audio?
  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
Mtx Thunder 280 Problem jamesl75 Car Audio 11 3rd November 2011 08:55 PM
MTX Thunder 8302 issue mbates14 Car Audio 14 5th January 2011 01:42 AM
MTX Thunder 6152 issue gsg529 Car Audio 10 7th July 2010 01:45 AM
MTX 280, no output, TAKE 2 ECM Car Audio 12 7th August 2009 07:52 PM
MTX 280, no output ECM Car Audio 15 6th August 2009 03:26 PM


New To Site? Need Help?

All times are GMT. The time now is 03:58 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