RSD 1200.1 smoking am I dead in the water?

Billy Sacco · Post by **Billy Sacco** » Wed Dec 10, 2008 8:52 am

I got an RSD1200.1 off ebay and hooked her up. Long story short after powering up the head unit I heard some pops and she was smokin. I was pretty miffed and thought I must have hooked it up backwards. Checked that and ground and power were hooked up correctly. No signal was even going to the sub as you have to turn the sub channel on the head unit for it to even send a signal. The fuse on the distribution block did not even blow. The fuses on the amp definitely looked popped. So do you all think the amp is gone or could changing the fuses maybe get it going again? I have a feeling that she is dead I smelled microchip smell really bad. I have not had bass in almost a year I was really looking forward to this

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joyride · Post by **joyride** » Wed Dec 10, 2008 9:56 am

Dont the rsd's have the opening in the chassis that makes it easy to drop little wire strands in them? Check to see if there are any loose wires in there. Im guessing the damage is already done, but this may be a reason for it.

Post by **Bfowler** » Wed Dec 10, 2008 10:22 am

no, they are sealed over with plexi glass.

can't really think of a weak point in the amp that would cause this.

Billy Sacco · Post by **Billy Sacco** » Wed Dec 10, 2008 10:36 am

Bfowler wrote:no, they are sealed over with plexi glass.

can't really think of a weak point in the amp that would cause this.

Yeah me either. I might have gotten a lemon. Figures I got a smokin deal on it

. I am going to recheck everything and I might try changing the fuses but the smoke and smell tells me she is bye bye. Time to call PG I do have another amp in reserve though thank god.

Post by **stipud** » Wed Dec 10, 2008 10:51 am

Flat rate of repair from PG is $175... a bit cheaper than you can get them on eBay.

thedeal7235 · Post by **thedeal7235** » Wed Dec 10, 2008 11:11 am

wild, ive had 2 of these, with NO ISSUES, and a rsd 500.4( i dont use, except ready as a backup amp), i hope its not anything major, ive been really happy with mine-good luck-

Billy Sacco · Post by **Billy Sacco** » Wed Dec 10, 2008 1:09 pm

stipud wrote:Flat rate of repair from PG is $175... a bit cheaper than you can get them on eBay.

Yeah I saw that. Sucks because that is more then I paid for the amp. I disconnected everything and the fuses in the amp are fine they did not burn out. So I guess I am definitely screwed.

thedeal7235 · Post by **thedeal7235** » Wed Dec 10, 2008 1:11 pm

do u have a dmm?

Billy Sacco · Post by **Billy Sacco** » Wed Dec 10, 2008 1:51 pm

Yeah its a cheapie though. But anyhow is there something I could check?

Billy Sacco · Post by **Billy Sacco** » Wed Dec 10, 2008 9:51 pm

Took the cover out and here is what I saw. I know the picture is crap sorry. There is some scorching under the rails (is that what they are called, they look like that anyway) closest to the speaker input. Only those four had it the rest did not have any scorching underneath. So how does something like this happen? Would this be an expensive repair if I had a local shop do it? Or would it be worth paying PG 175? Thanks all for any input.

Post by **Jacampb2** » Wed Dec 10, 2008 11:26 pm

Those are the power supply mosfets. Under normal conditions, they are very robust, but when thy go, they go catastrophically. Was the amp brand new? If not, I would suspect a shorted output transistor caused the problem. If it was new, then how sure are you of your sub and wireing there. Powering up the amp into a shorted VC or output wiring can cause this sort of thing. The protection is supposed to protect against this, but it is sometimes too late by the time protection trips.

Lots of things could cause this, in a brand new amp though, not so many. A cold solder joint on the gate to one of the mosfets can cause it to self destruct if the gate floats and power is applied, but that is about the only thing I can think of that would hit a brand new amp. A cold joint could make it through testing and inspection, and then fail open during vibration from shipping and installation. Regardless, all of the mosfets in that bank should be replaced, as one failure will stress all of them. This alone is a pretty good chunk of change. About $2-$3 each in small quantities. If there are other problems, that caused this, it will add up quickly. If there is a shorted output transistor, they will be much more expensive than the PS mosfets, and should also all be replaced for the bad channel, regardless of if all are bad or not.

Long story short, PG is probably your best bet. If you find a local shop that will work on it, they may not be able to do the work in the end. Most don't have any real experience with class D amps, and even if they do, most of the PG class d's I have had open have the identification markings from the class D amplifier section/module removed to prevent reverse engineering. I have seen a lot of products come from over seas like this, so it may not be PG's doing, but rather the facility putting them together.

Later,
Jason

Billy Sacco · Post by **Billy Sacco** » Thu Dec 11, 2008 8:31 am

Thanks so much for the thorough reply. I got the amp off ebay the previous owner claimed it was never powered up but it was opened so not sure. As far as the sub wiring it is a brand new sub I will check the wiring but pretty sure its ok how can I check if the VC is shorted? Thanks.

Post by **stipud** » Thu Dec 11, 2008 9:05 am

If you have a multimeter, hook it up to the + and - wires, set it to ohms, and let us know what the reading is.

Billy Sacco · Post by **Billy Sacco** » Thu Dec 11, 2008 7:00 pm

I took a reading off of the speaker cable and it read 4.5 ohms. I wanted it wired to 4 ohms so that is ok isn't it? When the amp went toast is it possible it could have messed up the sub?

Post by **Bfowler** » Thu Dec 11, 2008 7:09 pm

if its 4.5 ohms....the sub is most likey ok. a shorted sub would be much higher

Billy Sacco · Post by **Billy Sacco** » Thu Dec 11, 2008 7:35 pm

Thanks guys for all the help and suggestions I couldn't get a hold of the repairs person at PG today so I will try them tomorrow. I was afraid to connect the sub to another amp. Nothing like this has even happened before and I have installed a few different setups in my cars. Anyhow I might bite the bullet and get her repaired. I also saw a xenon on ebay and am tempted to have matching amps.

Post by **stipud** » Fri Dec 12, 2008 8:16 am

Bfowler wrote:if its 4.5 ohms....the sub is most likey ok. a shorted sub would be much higher

Short = 0 resistance
Blown = infinite resistance