Hmmm what do we have here?

[Mitch86 5,000+ posts]

Are these Mosfets that are burned up? Amp started smoking the other day so I took it apart to see what was up...found this:

Click to read more...

 

[Mitch86 5,000+ posts]

better pic:

 

[The_Grimy_One 10+ year member]

I am no repair guy, but I do believe those are the MOSFETS, yes.

 

[Mitch86 5,000+ posts]

I am no repair guy, but I do believe those are the MOSFETS, yes.

pretty sure they are too... wonder what makes them burn up like this tho?

 

[MisterDeadeye 10+ year member]

I would say that they are burnt up, yes. And yes, those are MOSFET transistors.

What amp is that? Gut pics of the whole thing?

 

[Mitch86 5,000+ posts]

early 2000 model Directed 1100d. Heres a cell phone pic of the guts:

 

[Mitch86 5,000+ posts]

Is it possible to DIY repair on this? Can I get the mosfets and solder them in myself? Having trouble locating the exact fets though //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

 

[gpgtp]

How good at soldering are you? Have you done electronic repairs before? I would think you could manage, but I would weigh what the amp and your time is worth, vs. taking it to a local repair shop. Just remember, if you do try to fix it dont get the board too hot. If you can get me the mosfet #'s, I can likely source you them. good luck.

 

[bubbagumper6 5,000+ posts]

Well since we can't see the part number, all of these geniuses telling you that's a mosfet are essentially just guessing. There's a lot of different electrical components that share the same package size, don't assume just because it looks like a mosfet it MUST be a mosfet...

Anyway, repairing amplifiers is not as easy as knowing how to handle a soldering iron, I would suggest you send it to someone before you try to repair it and damage it further.

 

[grandam888 10+ year member]

amp repair is not as simple as just soldering stuff in. and just because it "looks" like a mosfet, doesn't mean anything. could be a diode, rectifier, etc.

thing is when you blow a component in your amp, you may end up replacing 20 other components.

when i fixed my rockford t15002(and it ******), i replaced every resistor that ran parallel to the output fets, and even replaced 24 output fets on top of that. it can be very expensive, and time consuming. and if you don't know what your doing you could put hours into it, and re fry it.

my advice, go to diyaudio.com with this is if you plan on taking it on yourself. there are a few people there who know quite a bit about amp repair, and building. and will actually help you step by step on repairing your amp. if you do decide to repair it yourself, do yourself a favor and buy a NICE soldering iron. not some radioshack BS

 

[MisterDeadeye 10+ year member]

Well since we can't see the part number, all of these geniuses telling you that's a mosfet are essentially just guessing. There's a lot of different electrical components that share the same package size, don't assume just because it looks like a mosfet it MUST be a mosfet...
Anyway, repairing amplifiers is not as easy as knowing how to handle a soldering iron, I would suggest you send it to someone before you try to repair it and damage it further.

What else would need a heatsink? The only thing I could possibly think he's talking about is some kind of FET. It may not be a MOSFET, but it looks like a FET.

Taken from AmpGuts. Notice the heatsinks directly above the things he's talking about.

 

[Spooney 10+ year member]

Those are definitely burnt up power supply mosfets. Even if you are great as soldering it is not as easy as just replacing those burnt fets. Most of the time the power supply mosfets go after a failure in the output section of the amp. It's very common for an output mosfet/transistor to short or fail with no visible signs of destruction so you probably have another issue besides the burnt power supply fets. Occasionally the power supply fets may just go on their own but not usually. In addition to the burned parts you see you most likely would need to replace the gate resistors for each of the power supply mosfets(these are connected to the first leg of the fets) , replace the power supply driver transistors, and possibly even change out the pwm driver IC ( most likely a TL494 or an SG3525) . All of the power supply mosfets will need to be replaced too. Not just the burnt ones as they are all connected in parallel so they all saw the same stress that blew out those few. There may be a couple that still work but who knows for how long. It's always best to have all matched date coded parts when they are in parallel. This goes a long way towards increasing reliability as the parts would be as closely matched as possible. Uggghhh. I could go on all day. What I am trying to say is yes it is DIY repairable but you need the right knowledge and tools on your side. I wouldn't even think of trying this repair unless you have an excellent soldering iron,multimeter,and oscilloscope.

 

[grandam888 10+ year member]

What else would need a heatsink? The only thing I could possibly think he's talking about is some kind of FET. It may not be a MOSFET, but it looks like a FET.

Taken from AmpGuts. Notice the heatsinks directly above the things he's talking about.

i fixed a autotek oldschool mean machine once that had diodes on the heatsink.

 

[Mitch86 5,000+ posts]

Thanks for all the input guys. I doubt i'll put the time/effort into trying a repair since there are most likely more problems than just the fets... Looks like I'll be shopping for a new amp. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif