I recently had to give my wife's car a jump and had her hook up the battery cables (problem) she reversed the polarity and blew my Rockford Fosgate car amplifier in an instant ( my fault for not having and inline fuse for protection ). I'm wondering if any of you out there would be able to point me in the right direction as far as testing the amp component by component and where to start...so on and so forth. I know there is a good chance that something in the power supply section went first and maybe that's all --I also recognize the damage might be extensive. What do I want to test with my multimeter. I would be willing to take a high quality digital picture to send it to anyone who would need to see the basic layout of the board to give me instruction as to where to start testing and for what. Any responses would be much appreciated. Thank you.
Banned
Joined 2002
It may be worthwhile to see if there is a fuse in the supply area. Also, often there is a diode across the supply input, normally blocking. If the supply is connected in reverse, the diode conducts, and generally blows. It would blow in "shorting" mode, the amp will no longer work, (looks like a short), but removing the diode restore full functionality.
People at Rockford are not stupid. They realise that there are lots of possibilities that DIY (and official installation outfits) connect the supplies in reverse. It is cheaper for them to install SOME protection (a diode comes to 3 cts or so) rather than be faced with a host of returns they have to fix under guarantee or face a fight with a disgrunteld customer.
So, if you can't find it, take it to a car audio outfit and ask them to take a look at it. (Then again, they may just try to sell you a new one. I know, frustrating).
Jan Didden
People at Rockford are not stupid. They realise that there are lots of possibilities that DIY (and official installation outfits) connect the supplies in reverse. It is cheaper for them to install SOME protection (a diode comes to 3 cts or so) rather than be faced with a host of returns they have to fix under guarantee or face a fight with a disgrunteld customer.
So, if you can't find it, take it to a car audio outfit and ask them to take a look at it. (Then again, they may just try to sell you a new one. I know, frustrating).
Jan Didden
I would second the diode...
I would replace it rather than remove it just in case it happens again...
I've seen this sort of problem many times...
Usually an easy and cheap fix...
Just look where the B+ enters the main board. It's usually a pretty big diode... Often there will be no signs or burning but when you check it, it will be shorted.
Good luck,
I would replace it rather than remove it just in case it happens again...
I've seen this sort of problem many times...
Usually an easy and cheap fix...
Just look where the B+ enters the main board. It's usually a pretty big diode... Often there will be no signs or burning but when you check it, it will be shorted.
Good luck,
Banned
Joined 2002
What i mean was when a amp from rockford blows FRom stress or over power or a dead short or any other way.. they are not worth repairing. they never work the same when returned fro rockford.
i've had lots of friends send them back to rockford to get fixed and they just don't run or work properly when returned.
there value of the amp is junk. ill never buy a rockford amp again.
ALPINE ALL THE WAY.
i've had lots of friends send them back to rockford to get fixed and they just don't run or work properly when returned.
there value of the amp is junk. ill never buy a rockford amp again.
ALPINE ALL THE WAY.
Banned
Joined 2002
There's two of them at about 2 o'clock from the converter transformer centre. Can you do a resistance check on them with a multimeter, to see that they are shorted? Preferably after lifting one lead from the board. If you don't want to damage the board, just cut the lead above the board in such a way that you can resolder it afterwards.
WARNING: What you are about to do will invalidate the guarantee! Don't look at me!
Jan Didden
WARNING: What you are about to do will invalidate the guarantee! Don't look at me!
Jan Didden
"SQ".....first of all you broke the golden rule but I think maybe I can help if you tell me what model of amp you have because they use the same topology for most of them. The board looks ok from the pic but I did not see the onboard fuses so maybe you can take some other pics.
NEXT>>>>JasonL...you posted some statements which were uncalled for either out of ignorance or because you are a misinformed indivual....first of all fosgate does not sell crap when I was involved with Iasca for numerous years we used their equipment extensively and it performed well under anything we put it through......Only Jackasses have a problem with things when they dont know what they are doing....sorry bud but your statement has made me lose respect for you and maybe its because its just the youth coming out but it took alot of sweat and tears working with Fosgate designing vehicles for competition and I have numerous products still working flawlessly today before you probably knew what professional audio was.
I know I`m out of line in this post and moderate it as should but I`m offended when someone talks trash about fellow people I have respect for and who have contributed somuch time and effort to me
enough said
DIRT®
NEXT>>>>JasonL...you posted some statements which were uncalled for either out of ignorance or because you are a misinformed indivual....first of all fosgate does not sell crap when I was involved with Iasca for numerous years we used their equipment extensively and it performed well under anything we put it through......Only Jackasses have a problem with things when they dont know what they are doing....sorry bud but your statement has made me lose respect for you and maybe its because its just the youth coming out but it took alot of sweat and tears working with Fosgate designing vehicles for competition and I have numerous products still working flawlessly today before you probably knew what professional audio was.
I know I`m out of line in this post and moderate it as should but I`m offended when someone talks trash about fellow people I have respect for and who have contributed somuch time and effort to me
enough said
DIRT®
Banned
Joined 2002
Joe dirt i am not trying to offend any one. i'm just stating the facts. yes rock-ford amps WERE good. yes yes a few years ago they were the best amp going.
IM trying to say NOW there going down hill because there using cheaper parts crappie designs and yeah there not as good as they used to be.
i've see what the older amplifiers can do NOT as near what the new ones can and i'm not just saying this. i have heard a few major companies that sell these products all day say the same thing.
IM trying to say NOW there going down hill because there using cheaper parts crappie designs and yeah there not as good as they used to be.
i've see what the older amplifiers can do NOT as near what the new ones can and i'm not just saying this. i have heard a few major companies that sell these products all day say the same thing.
Banned
Joined 2002
Soundquest,
Yes those are the ones I meant. But looking again, I think they may actually be part of the secondary circuit. What I would expect should be one diode from gnd to B+, cathode at B+. Hold your soldering iron and snips, let Joe Dirt take a look at it. He obviously has direct experience in these things.
So, now I must go and put JasonL in my ignore file. My eyes hurt trying to decipher what is supposed to be English. Sigh.
Jan Didden
Yes those are the ones I meant. But looking again, I think they may actually be part of the secondary circuit. What I would expect should be one diode from gnd to B+, cathode at B+. Hold your soldering iron and snips, let Joe Dirt take a look at it. He obviously has direct experience in these things.
So, now I must go and put JasonL in my ignore file. My eyes hurt trying to decipher what is supposed to be English. Sigh.
Jan Didden
fried rockford
I tore into one of these a couple weeks ago. When the diodes failed in it, they about burned a hole in the board! The power supply diodes in these are usually in the same package as the output transistors. Look for a part number like MBR or close to it. The outputs and switching power supply transistors will usually start with IRF.
From the looks of it, I don't think you fried any of the diodes or transistors- or at least there aren't any obvious signs like there were with mine. I'd be more concerned with the power supply controller chip. Its the first device in the chain. If its not generating a square wave to the power supply FETS, nothing will happen. Everything else comes after it in the chain.
-Matt
I tore into one of these a couple weeks ago. When the diodes failed in it, they about burned a hole in the board! The power supply diodes in these are usually in the same package as the output transistors. Look for a part number like MBR or close to it. The outputs and switching power supply transistors will usually start with IRF.
From the looks of it, I don't think you fried any of the diodes or transistors- or at least there aren't any obvious signs like there were with mine. I'd be more concerned with the power supply controller chip. Its the first device in the chain. If its not generating a square wave to the power supply FETS, nothing will happen. Everything else comes after it in the chain.
-Matt
I opened up a pwr 650 and indeed they are protection diodes.
replace them and SQ please place a fuse by your battery for your vehicles sake.... amplifiers are cheap... vehicle computers are not and air bags deployed while in the vehicle do to malfunctions reach over 250 km/hr....not good if ya got something in your hand
Jason I here what you are saying and agree to some extent and I apologise for being harsh...the forum is meant hear everyones view points right or wrong
regards, JOE
replace them and SQ please place a fuse by your battery for your vehicles sake.... amplifiers are cheap... vehicle computers are not and air bags deployed while in the vehicle do to malfunctions reach over 250 km/hr....not good if ya got something in your hand
Jason I here what you are saying and agree to some extent and I apologise for being harsh...the forum is meant hear everyones view points right or wrong
regards, JOE
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