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How "NOT" to install a car amp

Posted: Fri May 25, 2007 1:27 pm
by 1moreamp
I had this amp show up today and i just had to share this with you guys. please attached pic, and tell me if you can see anything wrong :shock: :o :lol: :lol: :lol: :lol: :lol:

Enjoy C



Oh both channels are blown producing a 45 volt DC output to the speakers :roll:

Can anyone tell me why and how this happened???? :)


Please feel free to download this to your "installers hall of shame"

Posted: Fri May 25, 2007 1:29 pm
by VW337
Could those bits of wire stranding all over the FET's be part of the problem? :shifty: :doh:

Posted: Fri May 25, 2007 1:34 pm
by Capital_M
i dont think the picture is big enough :shifty:

Posted: Fri May 25, 2007 1:35 pm
by Capital_M
damn it, I r teh ban3d :cry:

Posted: Fri May 25, 2007 1:36 pm
by 1moreamp
VW337 wrote:Could those bits of wire stranding all over the FET's be part of the problem? :shifty: :doh:


And your the winner give the man a gift :!: :!: :!: :!: :lol: :lol: :lol: :lol:



Oh the moral of this story is:
"TRIM YOUR CABLES ELSEWHERE, BUT NOT OVER THE AMP" :oops: :oops: :oops:

Posted: Fri May 25, 2007 2:46 pm
by Thumper88
On another note, I like the fuse setup they're using.

Posted: Fri May 25, 2007 3:00 pm
by 1moreamp
Thumper88 wrote:On another note, I like the fuse setup they're using.

Yeah it failed to blow when both channels dumped 45 VDC into the speakers WOO-HOO!!!!! Can you smell the burnt voice coils ??? :roll: :lol: :lol: :lol:

Posted: Fri May 25, 2007 3:04 pm
by vin78
How does RF clamp down their FET's?
I remember their older ones used an aluminum bar and bolted it down to the case
Are there bolts that you removed already?

Posted: Fri May 25, 2007 3:09 pm
by 1moreamp
vin78 wrote:How does RF clamp down their FET's?
I remember their older ones used an aluminum bar and bolted it down to the case
Are there bolts that you removed already?

Hi Vin,
No this is a extention of the MESHA mounting method from the black and grind series till now. The power device is literally soldered to the panel by way of a re-flow oven. I use a re-flow work station to properly remove and replace these devices. If you use torches and 150 watt soldering irons they damage the power device and on power up of at full power draw of the amp it will fail. Its really a form of SMD mounting technology, really nothing new. :wink:

Posted: Fri May 25, 2007 3:16 pm
by vin78
What a pain...does it actually transfer heat better then a bolt or clamp?

Posted: Fri May 25, 2007 8:13 pm
by 1moreamp
vin78 wrote:What a pain...does it actually transfer heat better then a bolt or clamp?
Well I have not seen a real world data to the fact of better heat transfer, but Rockford claims it the best. One thing for sure it does lend itself to high speed build lines that pop amps off the line rather quickly. Or in other words it's assembly line fast and easy to build a lot of amps quickly without paying much attention to mechanical assembly.

In repair terms its also a sweet deal if you are Rockford and have a ten ton supply of these panels pre-built and ready to install. For independent tech's its a nightmare to rework these panel's. Very time consuming, and it DOES require special tools to do this sort of repair properly < namely re-flow solder tools and special low temp solder. These were not built using torches or 200 watt soldering tools. They were built in mass using re-flow ovens and low temp solder, and flux. All automatic just like baking bread or cakes. Most folks don't know this fact so they butcher these things working on them. I must have 2 dozen RF amps just sitting at my shop butchered by tech's using everything from blow torches to 300 watt soldering irons trying to repair these things.
Once they have done their damage it pretty much becomes a total rebuild to be able to repair and guaranty the repair, so most folks decide to buy new amps after they saved money getting a cheap repair that lasted 10 minutes to 1o days the last time because it was done wrong :roll:

Oh MESHA also allows you build and use very low grade <un-machined> mounting surfaces on your cheap sink case designs. By removing the machining step out of the sink build you save bundles of money by not needing a smooth flat surface to mount your power devices to. This also explains the concrete grade of heat sink compound that RF uses in their assembly of these amps. Regular heat transfer compound needs to be fine grade and able to work in close tolerance smooth flat surfaces. By using MESHA and raw metal surfaces with putty grade compound you just built the cheapest amp in the world, by designing around all the critical areas of assembly for the amp. < smart fella's at Rockford don't you think, or maybe just cheap , Hey? >

Posted: Sat May 26, 2007 12:33 pm
by shaheen
Better still do not use a RF amp as it may be able to get dropppings into the cases. Never had this problem with a proper amp ;) ;)

Posted: Sat May 26, 2007 1:52 pm
by 1moreamp
shaheen wrote:Better still do not use a RF amp as it may be able to get dropppings into the cases. Never had this problem with a proper amp ;) ;)

Well heres a fractoid from the past, I have a MS-2125 that was given to me about a year ago by a friend. And in 1992 the installer had the plexi cover off of it and was connecting it at the Autophile where I worked, and well he did the sprigs thing to the amp and I had to replace a brand new amps power supply :oops: :lol:

So it does happen to just about any brand including PG when the covers is removed during install :wink: In this case I still have not figured out how the installer got all that copper wire in the amp, unless maybe if he was really stoned, then maybe it makes sense :lol: :lol: :lol: It must have fallen in thru the air vents on the top cover, is all I can figure happened :idea:

And my friend Marko has a similar issue right now with a MS-2125 over in England. So shite happens if your not careful :D

Re: How "NOT" to install a car amp

Posted: Fri Mar 08, 2013 11:18 am
by IsakAlexander
BIG PITA to work on these.
I got rid of Rockford Fosgate T8002, giving me headache.
Still have a 150a1, easy repair with old school clamping, and a punch 600.5 which I will try to clamp the sub channel output devices.

Re: How "NOT" to install a car amp

Posted: Fri Mar 08, 2013 2:42 pm
by ttocs
wow thats a blast from the past....

Re: How "NOT" to install a car amp

Posted: Fri Mar 08, 2013 3:08 pm
by IsakAlexander
Yes I dont mind looking trough old threads and diggin´em up. Why not? Do every forum need a new thread about every little thing. Kind of boring looking trough 597 and 1/2 threads discussing the same. :-)