Hi everyone
Again here, with an old amp, I like, that I have received recently, and has come under the conditions that you can see in the photos.
Almost do not know where to start ...
Well as you can see, has been repaired before, the first thing that surprises me is that the power FETs are IRF3205, ¿,,? should be MTP75N05HD, right?
The IRF3205, are for lower power amps, right?
Also, there are several tracks on the printed circuit burned, the positive terminal was out of the motherboard, and melted plastic, there is an electrolytic capacitor, making bridge between some UC3625 pin, is this normal? Should I remove it, to repair the amplifier?
I guess this must be some kind of "trick" so that the amplifier has more performance ....
There are several pieces in the audio output, blackened, and its value does not look ... (I'll have to look them up in the wiring diagram ...)
Any idea where to start?
Any help is appreciated.
Again here, with an old amp, I like, that I have received recently, and has come under the conditions that you can see in the photos.
Almost do not know where to start ...
Well as you can see, has been repaired before, the first thing that surprises me is that the power FETs are IRF3205, ¿,,? should be MTP75N05HD, right?
The IRF3205, are for lower power amps, right?
Also, there are several tracks on the printed circuit burned, the positive terminal was out of the motherboard, and melted plastic, there is an electrolytic capacitor, making bridge between some UC3625 pin, is this normal? Should I remove it, to repair the amplifier?
I guess this must be some kind of "trick" so that the amplifier has more performance ....
There are several pieces in the audio output, blackened, and its value does not look ... (I'll have to look them up in the wiring diagram ...)
Any idea where to start?
Any help is appreciated.
Attachments
IRF3205 will work just fine in this amp with 47 ohm gate resistors. I have rebuilt many of these amps using those transistors and never had any power supply issues.
The mod you see was a factory service bulletin, although this one was done crudely but should work fine. It is suppose to eliminate excessive turn on draw making the amp squeal slightly upon powering up, and also gets rid of the turn on pop if you are using a head unit that has a higher low output voltage.
It looks like you have a shorted or leaking rail cap, and possibly the output inductor has shorted and burned everything in its path. If your gonna keep the amp I would fix it, if not cut your losses and rid it on ebay or something.
I am sure you have many burned traces and this amp will be time consuming to repair.
The mod you see was a factory service bulletin, although this one was done crudely but should work fine. It is suppose to eliminate excessive turn on draw making the amp squeal slightly upon powering up, and also gets rid of the turn on pop if you are using a head unit that has a higher low output voltage.
It looks like you have a shorted or leaking rail cap, and possibly the output inductor has shorted and burned everything in its path. If your gonna keep the amp I would fix it, if not cut your losses and rid it on ebay or something.
I am sure you have many burned traces and this amp will be time consuming to repair.
The trace near the rail caps burned because 12v contacted the heatsink. That could be the reason the other traces burned.
I thank you for answering, and I'm happy to have you for repairs.
I know it can be a difficult repair, Sean, but I like challenges, I am going to do ...
Well, I've repaired the tracks burned, I have reviewed all of the power MOSFET, the drivers, and the output MOSFET in Anyway, all transistors, and have not found any burned, weird, right?
I will connect it with a 10 amp fuse, and see what happens, how do you see? Or do you think something else should review before switching?
ah, and the resistors gate are 10 ohmios....
I know it can be a difficult repair, Sean, but I like challenges, I am going to do ...
Well, I've repaired the tracks burned, I have reviewed all of the power MOSFET, the drivers, and the output MOSFET in Anyway, all transistors, and have not found any burned, weird, right?
I will connect it with a 10 amp fuse, and see what happens, how do you see? Or do you think something else should review before switching?
ah, and the resistors gate are 10 ohmios....
Attachments
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So I did, Perry, and the other short, it has also been firmly tinned.
Well, I've connected has protection on a moment, and then is off, in the speaker connected, I put an mp4 at the entrance, and: to sing!
Curious, is not it? has been running more than half an hour with a generous volume, without any problems.
Perry, as always had every reason in the world, attached a picture so you can see the remains and signs were on the positive terminal and the back cover.
Again thank you very much for everything, and happy again! I wish you a happy day!
Well, I've connected has protection on a moment, and then is off, in the speaker connected, I put an mp4 at the entrance, and: to sing!
Curious, is not it? has been running more than half an hour with a generous volume, without any problems.
Perry, as always had every reason in the world, attached a picture so you can see the remains and signs were on the positive terminal and the back cover.
Again thank you very much for everything, and happy again! I wish you a happy day!
Attachments
The current passed through the heatsink and through the ground traces. It didn't pass through any electronic components.
Can you confirm that the camera you have is a Nikon E4100? If it is and someone wants a camera to take photos of boards, an E4100 is available on ebay for $13US (shipped).
Can you confirm that the camera you have is a Nikon E4100? If it is and someone wants a camera to take photos of boards, an E4100 is available on ebay for $13US (shipped).
Yes that must have been what happened, I'm glad you were so, the repair has been easier.
And yes, Perry, again, you're right, the camera is a Nikon Coolpix 4100, is already old, compared with those who are now, but still does the job. (that, ebay is a good price ...)
Greetings.
And yes, Perry, again, you're right, the camera is a Nikon Coolpix 4100, is already old, compared with those who are now, but still does the job. (that, ebay is a good price ...)
Greetings.
Glad to see it was an easy repair. It looked kinda bad at first but once you cleaned everything, it actually didn't look bad.
Congrats!!
Congrats!!
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