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 28th April 2006, 10:14 AM   #1
cruck00 is offline cruck00  United States
diyAudio Member
 
Join Date: Apr 2006
Location: Minnesota
Default Blown IRFZ44N

I am trying to fix an audiobahn a2300hcx amplifier that had burned out a couple of years back. The amp had pop spilled on it and it went through one of the fans and nothing seemed to happen at that time. The next morning the amp was fired up and it blew out and the protection turned on. I opened up the amp and noticed that three of the mosfets were definitely blown up so I replaced them with new IRFZ44n. There was some blackening on the resistors (gate?) right in front of them so I tested them to check their resistance and they tested out at the proper level. So I reassembled the amplifier and hooked it up to a battery to see if it would function properly and it blew two of the same fets again. One of the fets that I replaced appears to still be in good condition. I removed the two damaged fets and powered the amp up again. The fans and everything turn on but the protection circuit is still on. Can someone please tell me what would cause just these two mosfets to keep blowing up.
  Reply With Quote
Old 28th April 2006, 03:03 PM   #2
TO-3 is offline TO-3  Peru
diyAudio Member
 
TO-3's Avatar
 
Join Date: Feb 2004
Location: Phoenix, Arizona
Send a message via Yahoo to TO-3
Default Re: Blown IRFZ44N

Quote:
Originally posted by cruck00
I am trying to fix an audiobahn a2300hcx amplifier that had burned out a couple of years back. The amp had pop spilled on it and it went through one of the fans and nothing seemed to happen at that time. The next morning the amp was fired up and it blew out and the protection turned on. I opened up the amp and noticed that three of the mosfets were definitely blown up so I replaced them with new IRFZ44n. There was some blackening on the resistors (gate?) right in front of them so I tested them to check their resistance and they tested out at the proper level. So I reassembled the amplifier and hooked it up to a battery to see if it would function properly and it blew two of the same fets again. One of the fets that I replaced appears to still be in good condition. I removed the two damaged fets and powered the amp up again. The fans and everything turn on but the protection circuit is still on. Can someone please tell me what would cause just these two mosfets to keep blowing up.
An output channel might be bad, have you measured them? If one IRFZ44 blows, you need to replace them all as you are stressing out the part that is not blown.
__________________
Check out Tube Driver BLUE products at: www.tubedriver.com
  Reply With Quote
Old 28th April 2006, 03:11 PM   #3
cruck00 is offline cruck00  United States
diyAudio Member
 
Join Date: Apr 2006
Location: Minnesota
I am still new to car audio repair. I work for a large electronics manufacturer so I have the ability but I still have some questions. Are the output channels the ones on the opposite ends of the mosfets?
  Reply With Quote
Old 28th April 2006, 03:17 PM   #4
TO-3 is offline TO-3  Peru
diyAudio Member
 
TO-3's Avatar
 
Join Date: Feb 2004
Location: Phoenix, Arizona
Send a message via Yahoo to TO-3
Quote:
Originally posted by cruck00
I am still new to car audio repair. I work for a large electronics manufacturer so I have the ability but I still have some questions. Are the output channels the ones on the opposite ends of the mosfets?
Yes. Usually they are complimentary bi-polars. Measure from the middle pin to the outer pins to check if they're shorted. Replace all parallel components and I'd recommend that you replace the complimentary components as well.
__________________
Check out Tube Driver BLUE products at: www.tubedriver.com
  Reply With Quote
Old 28th April 2006, 03:21 PM   #5
cruck00 is offline cruck00  United States
diyAudio Member
 
Join Date: Apr 2006
Location: Minnesota
Should I replace the components on the opposite side of the board as well, even though they don't seem to have been affected?
  Reply With Quote
Old 28th April 2006, 03:24 PM   #6
TO-3 is offline TO-3  Peru
diyAudio Member
 
TO-3's Avatar
 
Join Date: Feb 2004
Location: Phoenix, Arizona
Send a message via Yahoo to TO-3
Quote:
Originally posted by cruck00
Should I replace the components on the opposite side of the board as well, even though they don't seem to have been affected?
No. If the other channel is not shorted you do not need to replace them. These are totally independent of the opposite channel.
__________________
Check out Tube Driver BLUE products at: www.tubedriver.com
  Reply With Quote
Old 28th April 2006, 03:31 PM   #7
cruck00 is offline cruck00  United States
diyAudio Member
 
Join Date: Apr 2006
Location: Minnesota
Alright, I will try replacing all of the fets on the bad channel and test the outputs. Then I will replace all of the outputs on that channel. I will also be replacing the resistors for each mosfet and output. I will have to wait a little while before I can actually replace these components because I will have to order some more mosfets and some outputs. Thanks for your help and I will post how everything turns out after I do the repairs.
  Reply With Quote
Old 28th April 2006, 03:32 PM   #8
cruck00 is offline cruck00  United States
diyAudio Member
 
Join Date: Apr 2006
Location: Minnesota
are there any other components that you would recommend replacing? and how do I know what wattage of resistor to use when replacing them?
  Reply With Quote
Old 28th April 2006, 03:39 PM   #9
cruck00 is offline cruck00  United States
diyAudio Member
 
Join Date: Apr 2006
Location: Minnesota
I do know the current ohm values just unsure about the wattage.
  Reply With Quote
Old 28th April 2006, 03:59 PM   #10
TO-3 is offline TO-3  Peru
diyAudio Member
 
TO-3's Avatar
 
Join Date: Feb 2004
Location: Phoenix, Arizona
Send a message via Yahoo to TO-3
Quote:
Originally posted by cruck00
Alright, I will try replacing all of the fets on the bad channel and test the outputs. Then I will replace all of the outputs on that channel. I will also be replacing the resistors for each mosfet and output. I will have to wait a little while before I can actually replace these components because I will have to order some more mosfets and some outputs. Thanks for your help and I will post how everything turns out after I do the repairs.
I would check the outputs before you replace the switchers in the power supply. You don't want to keep replacing power supply parts.
__________________
Check out Tube Driver BLUE products at: www.tubedriver.com
  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
Huf75337p3 in place of irfz44n? spooney Car Audio 10 9th August 2009 06:03 AM
Is there a difference in a IRFZ44 and a IRFZ44N? Itsme Car Audio 7 5th November 2007 11:33 PM
IRFZ44N Chip Question? Itsme Car Audio 12 29th October 2007 07:58 PM
need to find out which IRFZ44N to get..help please Wyldhorse Car Audio 2 14th July 2007 10:46 PM
Questions about mosfets IRF3205 IRFZ44N dB-r Solid State 3 6th December 2006 12:36 PM


New To Site? Need Help?

All times are GMT. The time now is 04:26 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