mtx 6500d not 1 ohm stable - 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 19th January 2012, 04:29 AM   #1
diyAudio Member
 
Join Date: Dec 2011
Default mtx 6500d not 1 ohm stable

I have read this thread in hopes of finding some useful information in repairing a 6500d that i put into a 1ohm load. The amp worked for about 30 secs then it just quit. I checked the 3 fues they were all blown. Keep in mind that the fuses were 15a. It calls for 25a. I put 3 new 25a and she started rollin again. I must say this amp is such a underated amp. I know its not a 1ohm stable amp but it lasted for about a week then one night boom it cut off and then i smelt it. I took the amp apart and imediatley noticed the input side mosfets were melted.

From the research i have done on this site i ordered some irf3205's to replace the 75339p.

I replaced them tonight and took some readings

FET601 climed to 900+
FET602 same
FET603 same
FET604 same

I got the readings with my DMM set to .OL and red probe on center pin and black probe on the right or left outer leg depending on which way your looking at it. If i reversed polarity i got the same reading but it was -984

Im afraid to power it back up due to maybe some other things i might need to look at like maybe R628 and R629 they look a little ruff compared to some of the others.

Last thing there are 2 fets labled REC601 and REC602. How should these read? Into the mega ohms like other fets?
  Reply With Quote
Old 19th January 2012, 05:36 AM   #2
diyAudio Member
 
Join Date: Dec 2011
Update!

I took the REC602 out of circuit and confirmed a reading of 0.000 in any configuration. It goes from .OL to 0.000 instantly while the REC 601 reads well into the 900's

The REC602 has U1620R CQ236 KAK on it

The REC601 has MUR1620C. N2 18 on it

Seems like same fet just different manufactors?

PS outta circuit means to desolder and remove from board? For testing purposes?? I got the same reading when the fet was on the board. Is this just to make sure its not being shorted out by something else
  Reply With Quote
Old 19th January 2012, 05:54 AM   #3
diyAudio Member
 
Join Date: Dec 2011
I know i keep answering my own questions but i wanna make sure my research is correct. These 2 rectifiers both have 1620 in their part #s so im gonna scoop 2 of these up to replace both at the same time. When i search online for u1620r i get mur1620r in my search results.
  Reply With Quote
Old 19th January 2012, 11:13 AM   #4
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
Click the red triangle in the left corner of one of your posts and ask a moderator to move the posts to a new thread. Tell them the subject that you want for the new thread and the numbers of the posts 111-113 as of now to be moved.

I'll try to answer your questions when it gets to the new thread.
  Reply With Quote
Old 19th January 2012, 11:21 PM   #5
just another
diyAudio Moderator
 
wintermute's Avatar
 
Join Date: Aug 2003
Location: Sydney
Blog Entries: 22
done
__________________
Any intelligence I may appear to have is purely artificial!
Some of my photos
  Reply With Quote
Old 19th January 2012, 11:33 PM   #6
diyAudio Member
 
Join Date: Dec 2011
Thanks!

After further investigation i gently touched touched resistors R628 and R629 and they basically just flaked off. I think these might be 0805's
  Reply With Quote
Old 20th January 2012, 01:18 AM   #7
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
They are 47.5 ohms. They are likely 0805s. Did they break into two pieces?

If not, are they still within tolerance?
  Reply With Quote
Old 20th January 2012, 01:37 AM   #8
diyAudio Member
 
Join Date: Dec 2011
They broke in half. Hopefully i can scoop up some of them tomorrow along with some Rectifiers that i discussed in an eariler post.

I have a Little AC to DC converter that i can select voltage on from 3-12 volts. Can i use this to bench test? I put my meter on it and it read just as if i was checking the voltage off my car battery.
  Reply With Quote
Old 20th January 2012, 02:28 AM   #9
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
I don't know if I just didn't understand what you posted or if there was some confusion on your part. The two rectifiers are different. The MUR1620CT and the MUR1620CTR are what you need. The 'R' version is the negative rectifier.

It depends on the current capacity of the 12v power supply.
  Reply With Quote
Old 20th January 2012, 04:25 AM   #10
diyAudio Member
 
Join Date: Dec 2011
Yes Thank you i seen where you mentioned this in a post i found earlier. If you hadnt have mentioned it above i woulda over looked that during my parts pick up i may end up ordering if they cant get.
  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 mike49504 Car Audio 16 26th September 2011 11:34 PM
MTX 6500d radwilsons5803 Car Audio 9 4th May 2011 07:10 PM
orion hcca250r, kicker zr 1000, mmats d800.2, mtx 6500d, mtx 942, rockford punch 45, ernie cosillos Swap Meet 3 12th February 2011 11:14 AM
MTX 6500D m4ick Car Audio 14 2nd February 2011 12:43 AM
Mtx 6500d mike49504 Car Audio 17 17th January 2010 07:45 AM


New To Site? Need Help?

All times are GMT. The time now is 07:01 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