Rockford Fosgate Type RF X6 - 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 20th November 2012, 08:40 AM   #1
diyAudio Member
 
seankane's Avatar
 
Join Date: May 2010
Location: Washington State
Default Rockford Fosgate Type RF X6

Hello I have a RF type RF X6 in for repair. The board number is PC-3757-D.

I powered the amp and it was powering up drawing a little much current but slowly bleeding down to normal draw and staying there. The amp is in protect.

There is no DC on the output terminal and the amp is producing around 90v rail.

I removed the cover. I first replaced U21 and same result powered up in protect. I then noticed a component not looking right on the board. The component was a MC340 64P-5 which is a under voltage sensing circuit.

Leg 1 which is the reset was soldered to a solder bridge bewtween pins 1 and 2 of the LM339D, Leg 2 which is input was soldered to R65 a smd resistor marked 4120, Leg 3 which is ground was soldered to a spot on the board which obviously must be connected to ground but without removing alot of components or having a schematic I have no idea where it goes.

I thought to remove it and power up the amp. I did. The amp now stays powered up even with the remote wire removed. You have to unhook power or ground then it shuts off. It will stay powered up unless you remove the power or ground even if the remote is used to power the amp initially but then unhooked.

I looked a little closer under the magnifying glass and found pin 13 of the LM339 to be burned off of the IC or removed by someone, this pin is OUT4 on the data sheet.

I know the LM339 can shut down the amp for low voltage and thermal protections and I was wondering if it could trip the protect light as well? The board looks to be set up like a BD1000 just a little fancier with TO-247 outputs instead of TO-220. Thats why I suspected U21 upon first thoughts.

I will be replacing the LM339D just wanting some input from anyone who is interested and thinks this is an odd problem. I must fix the LM339D before I can further troubleshoot, and then move on to testing the outputs and such to see if a shorted output is setting the protect light off.

Any help would be great!!!
__________________
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

Last edited by seankane; 20th November 2012 at 08:43 AM.
  Reply With Quote
Old 20th November 2012, 08:46 AM   #2
diyAudio Member
 
seankane's Avatar
 
Join Date: May 2010
Location: Washington State
Here is a pic of the board as well...............
Attached Images
File Type: jpg TYPE RF X6 001.jpg (1,017.4 KB, 47 views)
__________________
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 20th November 2012, 10:09 AM   #3
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
The 339 can't cause the protect LED to light up.

It's likely due to a brief over-current pulse as the amp tries to power up or a defective U18.
  Reply With Quote
Old 20th November 2012, 10:23 AM   #4
diyAudio Member
 
seankane's Avatar
 
Join Date: May 2010
Location: Washington State
OK I replaced the LM339 and the amp powers up and down fine now but still in protect. I found C13 was burned in half which connects pin 7 of U7 and U8 to something.

I am not sure what part number C13 is it is one of the little rectangular capacitor orange in color. The ones around it are marked 104V N0 103.

I will replace U18.

For a future reference just in case I have shorted outputs where can I find a sub for SFH154 and SFH9154 every where I look says obsolete!!!
__________________
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 20th November 2012, 10:34 AM   #5
diyAudio Member
 
seankane's Avatar
 
Join Date: May 2010
Location: Washington State
Do you know the value of C13 or have the schematic??

I replaced U18 the protect light is no longer bright but very dimmly lit now and I hear a buzzing on the board as C13 is removed and its coming from that area. Is there any value I can replace it with for testing??
__________________
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 20th November 2012, 10:57 AM   #6
diyAudio Member
 
seankane's Avatar
 
Join Date: May 2010
Location: Washington State
I found a defective U6 MIC4420 CT replaced it and now the amp powers up goes out of protect and as soon as the protect light goes out the amp starts squeeling and has current draw.

Could this be due to C13 missing?
__________________
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 20th November 2012, 11:25 AM   #7
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
It could be part of the problem. It's a 0.1uf tantalum capacitor.

It's also possible that the opto-coupler driving the 4420 was damaged when the driver failed.
  Reply With Quote
Old 20th November 2012, 11:26 AM   #8
diyAudio Member
 
seankane's Avatar
 
Join Date: May 2010
Location: Washington State
Could the opto coupler cause current draw and squeeling?
__________________
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 20th November 2012, 11:29 AM   #9
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
It's possible. Anything in the drive circuit could cause that. Replace the cap (with any 0.1uf or greater cap) to see if it helps.

Don't operate it for long like that. It can cause the outputs to fail.
  Reply With Quote
Old 20th November 2012, 11:31 AM   #10
diyAudio Member
 
seankane's Avatar
 
Join Date: May 2010
Location: Washington State
I thought the tantalam caps were through hole devices like on the bd1000 and bd1500 these are smd, are they the same value then?
__________________
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

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 Type RF X2 seankane Car Audio 3 8th February 2012 05:00 AM
Rockford fosgate 4.6 X mike49504 Car Audio 14 28th May 2011 03:35 PM
Rockford Fosgate RF? - Model unknown sync clips Dr Zeus Car Audio 40 10th December 2010 01:17 PM
Rockford Fosgate dtisme Car Audio 1 5th October 2010 11:39 PM
rockford RF X3 scampo77 Car Audio 23 8th April 2010 12:43 AM


New To Site? Need Help?

All times are GMT. The time now is 12:35 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