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 12th December 2011, 09:09 PM   #1
diyAudio Member
 
josesony68's Avatar
 
Join Date: Feb 2011
Location: Caceres
Default Rockford Fosgate 1501bd preview Repairing

Hello, today I received this amp, I bought on eBay.
I keep thinking, how someone can destroy an amplifier of this form.
I counted seven mosfet destroyed, burned six resistors, four capacitors swollen, two ceramic pieces are missing, and sure there is more bad parts.
I do not know where to start.
Do not enter my head, how could that happen.
Anybody can explain me?

Tomorrow I'll start to repair it.
Attached Images
File Type: jpg DSCN2985.JPG (768.7 KB, 312 views)
File Type: jpg DSCN2988.JPG (756.5 KB, 292 views)
File Type: jpg DSCN2991.JPG (740.9 KB, 269 views)
  Reply With Quote
Old 12th December 2011, 10:07 PM   #2
amc32 is offline amc32  United States
diyAudio Member
 
Join Date: Mar 2008
Your in luck, its not the worst. Atleast the entire citcuit board isn't burnted. Damage like this comes from user/installer error. Unrealistic expectations, such as to play@ .5ohm with only 11volts while amp is running full tilt clipping.
__________________
...............I Hear in color.................
  Reply With Quote
Old 12th December 2011, 10:15 PM   #3
diyAudio Member
 
josesony68's Avatar
 
Join Date: Feb 2011
Location: Caceres
Yes, it is true, however, it still seems a savage ...
Why some people want to get more power than that which comes from the factory?
Why not buy a more powerful amplifier, instead of using a little force it to give more than what can not?
I do not understand.
  Reply With Quote
Old 12th December 2011, 11:35 PM   #4
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
Some people think that they know more than the next guy if they can run their amps below the rated impedance.

This is one reason that I no longer work on MMATS amps. It seems that every owner thinks that every MMATS amp can and should be driven into a 0.25 ohm load. There's no way to convince them otherwise. I've given up trying.

This is not a difficult repair. When they come in with all of the power supply FETs blown along with blown outputs, it's much more difficult.

I only see one swollen cap next to one of the regulators. Which others are swollen?

Do you have a scope?
  Reply With Quote
Old 12th December 2011, 11:37 PM   #5
diyAudio Member
 
seankane's Avatar
 
Join Date: May 2010
Location: Washington State
That amp does not look that bad at all that should be an easy repair. Looks like one bank of output fets fried could have been a blown sub. You first need to remove all the shorted output fets from the circuit.

I am sure the MIC4420CT low side mosfet driver will be bad after a failure like that. You will need a few IRF3415 and IRF6215 output fets and some gate resistors and a driver likely.

Does the amp power on is it in protect whats the scoop?
__________________
Pyramid 52 Amp Power Supply----Fluke 787 Processmeter----Tektronix 465 Scope----Velleman HPS40 Scope----Soldering Iron----Desoldering Iron----Hejet HJ 500-S Heatgun----DM4070 Digital LCR Meter----Propane Torch
  Reply With Quote
Old 13th December 2011, 01:24 AM   #6
Dr Zeus is offline Dr Zeus  United States
diyAudio Member
 
Dr Zeus's Avatar
 
Join Date: Oct 2010
Im sure I am not the only one who sees a ton of gobldy gook inside the leftern torriod. What the heck is all that grey moosh? If the transformer is shorted you'll have to make sure it is able to be repaired or replaced before buying any other parts.
  Reply With Quote
Old 13th December 2011, 03:12 AM   #7
diyAudio Member
 
Join Date: Sep 2009
Location: Wisconsin
They coat the transformers on the larger amps.

Sent from my DROID using Tapatalk
__________________
BK 1544 40Mhz scope.....Pyramid PS-26KX supply.....Tenma 72-380 Func. Generator
  Reply With Quote
Old 13th December 2011, 03:22 AM   #8
diyAudio Member
 
seankane's Avatar
 
Join Date: May 2010
Location: Washington State
Some of the bd's were notorious for "whining" it was the torroid I think they actually vibrated. Didnt really hurt anything but was annoying and if you put your hand on it and applied pressure it would stop.

Rockford started coating them to eliminate the problem. That one looks like it was done by someone other than Rockford. I usually dont coat them like that as it would hold alot of heat.

I have used silicone and epoxy both to eliminate the whine.
__________________
Pyramid 52 Amp Power Supply----Fluke 787 Processmeter----Tektronix 465 Scope----Velleman HPS40 Scope----Soldering Iron----Desoldering Iron----Hejet HJ 500-S Heatgun----DM4070 Digital LCR Meter----Propane Torch
  Reply With Quote
Old 13th December 2011, 03:26 AM   #9
diyAudio Member
 
seankane's Avatar
 
Join Date: May 2010
Location: Washington State
Some of the BD amps mainly the 1500's the torroids rubbed on the bottom cover and shorted out. This was another reason for the coating.

I will coat them and sometimes use spacers in between the sink and bottom cover.
__________________
Pyramid 52 Amp Power Supply----Fluke 787 Processmeter----Tektronix 465 Scope----Velleman HPS40 Scope----Soldering Iron----Desoldering Iron----Hejet HJ 500-S Heatgun----DM4070 Digital LCR Meter----Propane Torch
  Reply With Quote
Old 13th December 2011, 04:04 AM   #10
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
I agree, it's likely to quiet the transformer. It was a complaint from a lot of people who had the amps inside the car or could hear it when their rear seats were down.

I also avoid coating them when possible. Sometimes you just need to move the windings a bit to quiet them.
  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
Rockford Fosgate Power 851X repairing josesony68 Car Audio 32 24th September 2011 03:21 PM
Rockford Fosgate 1501bd Repairing josesony68 Car Audio 35 11th September 2011 03:24 PM
Support to repair Rockford Fosgate 1501bd amplifier josesony68 Car Audio 2 27th July 2011 07:09 AM
Repairing Rockford fosgate punch 40X2 channel help chipper Car Audio 17 26th August 2010 10:29 PM
Repairing Rockford Fosgate 250a2 03Jeep Car Audio 6 18th January 2006 02:02 PM


New To Site? Need Help?

All times are GMT. The time now is 08:28 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