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Discussion Starter #1
I'm wondering if you amp guys can help. I just bought an old RF 200a4 that came as a bundle with a pair of speakers. I heard the amp briefly in the seller's vehicle and everything seemed fine. After hooking it up to my 6.5" components only (2 channel into passive crossovers), it ran very hot and finally shut down in protect mode. It sounded good while running but gets scary hot (can't even touch the enclosure). I thought that the speakers might be the problem but an ohmmeter on the crossover inputs showed ~3.8 - 4 ohms. As a sanity check, I temporarily hooked the speakers up to an old Audio Art amp which drove them nice and cool without an issue. So, my conclusion is that it's not the speakers.

The install is on a Z3 so the amp is right next to the battery and the power runs are direct and short using 8awg. The amp gets hot quickly no matter what the gain or volume is set at. So, in desperation, I unhooked the speakers and simply powered the amp with no load to see what would happen. Again, within about 5 minutes, you couldn't even touch the sinks even with no load! So, I'm pretty certain this thing is toast unless anyone has any ideas. If so, is it worth trying to get it fixed (cheap fix) or does it make sense to peddle on ebay as "needs repair". Any suggestions would be welcome.
 

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I'm gonna chock it up to the amp being the issue here. Sounds like its shorted internally or something.
 

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I have a crossfire vr 2000d that does the same thing. the amp heats up very quickly and makes no sound with the subwoofer. the thing just switches from power to protect mode. I think both of us our now proud owners of some of the most expensive anchors known to man. I think all we can do is laugh because the damage is already done
 

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Open the thing up, it's not like you have a warrantee to worry about... Have a look and see if there is something grossly out of place??

what if you power it up with speakers attached, but no RCA??? Something to try...
 

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Discussion Starter #5
Well, I opened it and took a look. I looked at the output transistors and the area where I expected the most heat to be generated and everything looked OK. Then, I saw a piece of electrical tape in the middle of the board that covered some components. This didn't look normal so I gently pried it away and uncovered a desperate fix from a previous owner. It seems one of the circuit traces separated from the board and underneath the tape the trace had split and come apart. I think the owner was trying to keep the two ends of the traces connected and the whole thing held down to the board by the tape. Yikes. It was obvious that the area had gotten hot as a small bar code label next to the trace had turned brown from heat. Anyway, I'm going to deal with this over the weekend. I'll cut the traces back where they're still attached to the board and jump the two ends with an insulated jumper wire. We'll see if this cures the problem. Thanks for the replies and I'll post back with the results.
 

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Before you use it put a meter on the speaker terminals and make sure it is not putting out DC current to the speakers. Should show under 50mv usually, just powered up with nothing hooked to it. Certainly should not heat like that.
 

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Discussion Starter #7
So here's the end of the saga. I jumped the broken trace and ran the amp only to find that the amp was heating up the same way as before. I looked over the board and components really well and didn't see any obvious problems or bad solder joints. Before I toss the amp in the trash, I had to try one more thing. There are 4 trimmer potentiometers on the board and I thought that maybe the genius that opened up the amp and taped the circuit trace may have messed with them. I turned them all 1/4 turn counterclockwise (hoping that I was lowering their function) and tried the amp again. I wasn't positive but to my ears the soundstage sounded a little different and better than before. I sat in the car and listened to a few songs before I dared to get out and touch the amp. If it was hot, I had made up my mind that I was tossing it. I put my hand on it and it was stone cold. Not even warm. Unbelievable. This is my new amp.

FYI, I paid $100 for this amp and a pair of used BA Pro 6.5's (which I didn't hear but was assured they worked fine) off of craigslist. I went through a similar ordeal with the speakers because one of the tweeters didn't work. The seller must have been happy to get rid of these two broken components for cash. Well, I found a broken lead-in wire on the tweeter and the fix was pretty simple. The speakers sound great and now that the amps working, I finally feel like I didn't get ripped off. Thanks again for the help.
 

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That's sweet... It's prolly bias or something, so it should really be looked at by a professional, but, you got it working at least, and took care of a serious potential problem..

I used to repair a lot of traces in HU's after someone would pop an output IC to the point of scorching some traces.. you got a good solder contact I would assume? .. I used to scratch off the board epoxy with a razor blade and solder to that..

I know of a place you might be able to send it, if it means enough to you..
 

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Discussion Starter #9
Thanks Aaron, I'm going to use it for a little while and see how it goes. I was pretty lucky with the jumper fix, it wasn't in the middel of a bunch of surface mount stuff. I was able to grab on to a lead of a diode at one end of the jumper and got a nice sturdy connection. At the other end, the trace went into a nice big area that was easy to solder after scraping off some coating.
 

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Discussion Starter #11
Hate to resurrect this thread, but I thought I'd give an update. The amp failed not long after I made the changes to the potentiometers. The amp has a blown mosfet and won't power up. Anyway, I could have lived with that but before the amp stopped working, it fried the voice coil in one of the BA woofers. Well, I guess you win some and you lose some. I was all giddy about my $100 score. Now, not so much...
 
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