MTX TA81001 - Page 2 - 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 16th June 2012, 08:06 AM   #11
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
If LED400 is lit, post the DC voltage on all legs of the op-amp closest to the opto-couplers.
  Reply With Quote
Old 17th June 2012, 04:18 AM   #12
diyAudio Member
 
Join Date: Sep 2006
LED 4001 is not lit.. Only Led 401 is lit up..

Heres the voltages on the op-amp though..

Pin 1:-13.92
Pin 2:0.14
Pin 3:0
Pin 4:-15.48
Pin 5:-12.60
Pin 6:-11.70
Pin 7:-3.95
Pin 8:15.01
  Reply With Quote
Old 18th June 2012, 03:32 AM   #13
diyAudio Member
 
Join Date: Sep 2006
Amps fans are also not spiining when powerd up not sure if that normal
  Reply With Quote
Old 18th June 2012, 12:35 PM   #14
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
The fans don't spin at idle.

That op-amp appears to be defective. I would expect to see pin 7 very near the negative 15v with the voltages that you posted.

What is the DC voltage measured directly across the speaker terminals?
  Reply With Quote
Old 19th June 2012, 01:15 AM   #15
diyAudio Member
 
Join Date: Sep 2006
Did not replace the op-amp yet..

Voltage measured directly across speaker terminals is 0.70 volts
  Reply With Quote
Old 19th June 2012, 01:58 AM   #16
diyAudio Member
 
Join Date: Sep 2006
Replaced the op-amp with a brand new one and now R145 and R146 blew a hole right thru them..


They sit in front of the rectifiers on the back side of the board
  Reply With Quote
Old 19th June 2012, 02:11 AM   #17
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
Those are in series with the transistor that's used for the +15v regulator. The regulator may have failed. Check all components in the regulator circuit.
  Reply With Quote
Old 24th June 2012, 04:37 AM   #18
diyAudio Member
 
Join Date: Sep 2006
Ok I found FET191 shorted across all 3 legs..

The markings on it are PHP 30NQ15T


The other amp i have here is the excat same model and in fet191's location there is a IRF540...


Will the 540 work in this amp as well ?
  Reply With Quote
Old 24th June 2012, 02:41 PM   #19
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
There was a high failure rate for the 540s. They may have used the 150v transistors for a reason. The IRF3415 may be a better choice and is likely to be more reliable than the 540 (rated for both higher voltage and current).
  Reply With Quote
Old 24th June 2012, 07:43 PM   #20
diyAudio Member
 
Join Date: Sep 2006
replace Fet191 with an IRF3415..

Checked compnents in that area all test good also rechecked the power supply fets and outputs they also check good..

When when applying the remote wire the amp will draw excessive current ..

Any ideas?
  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 6500d radwilsons5803 Car Audio 9 4th May 2011 08:10 PM
MTX TA8502 DClark3one3 Car Audio 1 28th April 2011 04:47 PM
orion hcca250r, kicker zr 1000, mmats d800.2, mtx 6500d, mtx 942, rockford punch 45, ernie cosillos Swap Meet 3 12th February 2011 12:14 PM
Mtx 2300 mike49504 Car Audio 39 20th January 2010 07:46 AM
Help me fix MTX 152 and MTX 500D hakentt Car Audio 94 8th December 2008 07:26 PM


New To Site? Need Help?

All times are GMT. The time now is 04:31 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