I have a sundown SAZ 3000 that works other than a crazy issue its had since day 1 that Ive owned it, and it started one day when the previous owner was using it. I bought it "blown".
The amp used to turn on and play just like it should everyday. Then it slowly got to where occasionally, it would turn on and go into protect, or, it would turn on and the speaker outputs get a random DC current. Not a steady current, its a BANG BANG BANG through the subs, very loud. Some days the amp would work fine, sometimes for weeks... well now it does it every time it turns on. Its been doing this for about a year and slowly getting worse.
Heres the catch it does it when the amp is cold, but if you keep turning it back on, over and over, it will eventually play just fine. The amp does it even less once its hot.
The amp has been repaired before, it looks like all the FETs were replaced as well as the voltage regulators, but not the power supply or output drivers. The short is quite loud actually, heres a video
https://www.facebook.com/photo.php?v=10153217588545720
The noise is coming from the little blue boxes, Ive been told they are filter capacitors. For the sake of the video, I pulled one side of R13 which disabled the protect circuit because normally it would do it a few times then go into protect. I removed one that sounded like the noise was coming from it, and powered it up, then the noise started coming from the next one in line. Removed that one, and the same thing happened... so I assume they arent the problem.
I dont know much about schematics and circuits or what not, but have a multimeter and can solder/desolder pretty well.
The amp used to turn on and play just like it should everyday. Then it slowly got to where occasionally, it would turn on and go into protect, or, it would turn on and the speaker outputs get a random DC current. Not a steady current, its a BANG BANG BANG through the subs, very loud. Some days the amp would work fine, sometimes for weeks... well now it does it every time it turns on. Its been doing this for about a year and slowly getting worse.
Heres the catch it does it when the amp is cold, but if you keep turning it back on, over and over, it will eventually play just fine. The amp does it even less once its hot.
The amp has been repaired before, it looks like all the FETs were replaced as well as the voltage regulators, but not the power supply or output drivers. The short is quite loud actually, heres a video
https://www.facebook.com/photo.php?v=10153217588545720
The noise is coming from the little blue boxes, Ive been told they are filter capacitors. For the sake of the video, I pulled one side of R13 which disabled the protect circuit because normally it would do it a few times then go into protect. I removed one that sounded like the noise was coming from it, and powered it up, then the noise started coming from the next one in line. Removed that one, and the same thing happened... so I assume they arent the problem.
I dont know much about schematics and circuits or what not, but have a multimeter and can solder/desolder pretty well.
I will try that. I have turned it on several times out of the heatsink and it does the same thing. Right now I have D13 pulled (its right next to the driver board, but not on it) which I was told would disable the protect circuit. I did that so I could take that video.
It is very difficult to get it to stop shorting and its terrifying while its doing it.
YES, work has been done to it previously. Not by me. The output and power supply mosfets have all been replaced. Both the power supply and output gate resistors and drivers all look original. The middle 2 things between the power supply/output fets (voltage regulators?) have been replaced as well.
Tried turning on the amp with no driver board and it did fine. Took the driver board out of another 3k I have and swapped it into this one and its shorting again and going into protect. I dont understand.
I did find this though. Never noticed it before, someone has obviously replaced this cap for some reason.
Picture on the top is my amp, picture on the bottom is what it should look like. The blue cap is the one in question. The cap itself is rated 100uf and 50v. I pulled a 100uf 25v cap (whats supposed to be there) out of another amp I have laying around and replaced it.
Amp seems to short out faster now for whatever reason.
I did find this though. Never noticed it before, someone has obviously replaced this cap for some reason.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Picture on the top is my amp, picture on the bottom is what it should look like. The blue cap is the one in question. The cap itself is rated 100uf and 50v. I pulled a 100uf 25v cap (whats supposed to be there) out of another amp I have laying around and replaced it.
Amp seems to short out faster now for whatever reason.
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