MTX Thunder 81000D Easy/Cheap Repair? [Pics]

[LGK 10+ year member]

So a buddy was drunk and decided to play with his system, ended up dropping the chassis onto his live power wire, poof magic smoke he told me.

So, I'm under the assumption these are mosfet chips? If anyone could give me info on what they are, where I can buy them and if it's a simple job of resoldering on new chips? Thanks in advance!

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[grimreper912003 5,000+ posts]

Probably blew the power supply fets. All the power supply fets will need to be replaced. I would recomend sending it to someone as something else may have blown, which could cause the amp to quickly blow again once started up.

 

[jco1385 5,000+ posts]

//content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

 

[LGK 10+ year member]

Those are the only fet chips blown, the rest are 100%.

Just looked @ the sticky threads about amp repair think I'll get in touch with some of those companies and see if he just wants me to send it out or what.

Thanks.

 

[LGK 10+ year member]

No go on paying $75-120+ for labor, shipping, parts, blah blah blah.

So back to the orignal question, where can I buy direct replacement's of these 8 fet chips that blew.

I'm just gonna resolder them, if it works great, if it works then blows up and is worse off then it is now, oh well.

As long as the chips are under $25 for 8 of them he's willing to throw away $25 if it doesn't end up working out.

*Edit*

Through the mircle of google I found a few sites selling mosfet chips, but there's so many to choose from gah! Any help would be appreciated... if no luck I'll completely remove the chips and throughly inspect them to find any kinda identifying marks... but if someone knows of the top of they head it'd help a shitload right now //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[ampjunkielikeme 10+ year member]

changing out the burnt transistors will probably not "fix" the amp... you have to have special equipment and know your stuff to repair amps .....

i wish it was just as easy as changing a few burnt parts and your amp works again...its just not like that at all...their are other parts in amps that blow and never show signs of them being bad. and you will never find them unless you know what you are looking for....

and the part numbers on right on top of the blow parts....if you can read them....

 

[LGK 10+ year member]

I get it, and appreciate you trying to help me.

But remember this isn't my amp, so I can't do with it what I please, and he thinks it's outrageous to pay $25(at the least) MORE then he paid for the amp itself to repair it. It's like buying a tv, having it fall over & crack the screen, then having the repair shop tell you "well, your cracked screen is gonna cost more to replace/repair then it would to buy a new tv". Although he got a steal on that amp to begin with, he just can't justify the cost, plus he got a kid he recently had, so it wouldn't be the end of the world if I can't fix it and he doesn't have beats. DIYAudio.com helped me out on my first post //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif dude told me exactly which transistors and gave me 4 links to sellers! thanks!

/thread

 

[midnightg35x 10+ year member]

I'd say you have to replace the gate resistors also. I had a MTX Thunder 4202 that I repaired the power supply FETs. It uses the same ones as that MTX. The gate resistors were also toast. Everything else was fine. As ampjunkie said, the models of the FETs should be right on the FET. At least one should be clean enough to read //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Original FET: http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=HUF75339P3-ND

Upgraded FET (I used these in my repair): http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=IRF1018EPBF-ND

 

[djman37 5,000+ posts]

I get it, and appreciate you trying to help me.
But remember this isn't my amp, so I can't do with it what I please, and he thinks it's outrageous to pay $25(at the least) MORE then he paid for the amp itself to repair it. It's like buying a tv, having it fall over & crack the screen, then having the repair shop tell you "well, your cracked screen is gonna cost more to replace/repair then it would to buy a new tv". Although he got a steal on that amp to begin with, he just can't justify the cost, plus he got a kid he recently had, so it wouldn't be the end of the world if I can't fix it and he doesn't have beats. DIYAudio.com helped me out on my first post //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif dude told me exactly which transistors and gave me 4 links to sellers! thanks!

/thread

good luck, he didn't follow rule #1, unhook the battery FIRST and he dropped the + wire on the - side of the circuit //content.invisioncic.com/y282845/emoticons/eek.gif.771b7a90cf45cabdc554ff1121c21c4a.gif keep up posted on if just replacing the FETs worked.

 

[jco1385 5,000+ posts]

just sell it as blown, and take that money and buy another amp.

 

[MakeshiftAudio 10+ year member]

I've seen this enough times to say it will cost you a bit. You will have to replace all the fets (Power supply and output fets). What happens most of the time is that the output fets fail for a reason or another, shorting the rails of the SMPS, which can cause them to do what is pictured here, one in parallel blowing, then the next, until the whole branch of each branch dies.

Since the fets are all in parallel to their own in each branch, you will need to replace all of the SMPS fets. The output bridge is probably shorted as well, so the same thing applies to it.

What are the #s on all of the fets, and give them by row as well.

Edit: Just read the first post. You probably just need to replace the SMPS fets, since from the B+ rail, there is a direct path to ground through the SMPS fets. There might be more damage, but this I know is one thing that happened, and how it happened.

 

[Boomin_tahoe 5,000+ posts]

Hahaha...I just sold that amp on Ebay not too long ago. Call the folks at MTX and they'll repair it for ya for like 100 bux plus shipping. You'll need a RA # tho which they will provide over the phone. I used to send them a lotta amps for repair....and they do a pretty good job of customer service.

 

[Boomin_tahoe 5,000+ posts]

good luck, he didn't follow rule #1, unhook the battery FIRST and he dropped the + wire on the - side of the circuit //content.invisioncic.com/y282845/emoticons/eek.gif.771b7a90cf45cabdc554ff1121c21c4a.gif keep up posted on if just replacing the FETs worked.

Remember he did say his buddy was drunk....cant think str8 with alcohol inside ya.

 

[jco1385 5,000+ posts]

Hahaha...I just sold that amp on Ebay not too long ago. Call the folks at MTX and they'll repair it for ya for like 100 bux plus shipping. You'll need a RA # tho which they will provide over the phone. I used to send them a lotta amps for repair....and they do a pretty good job of customer service.

i called them about fixing my old 1501d and they said that they wouldnt fix it, just take it as a trade for a new amp. that was like 2 years ago.

 

[Boomin_tahoe 5,000+ posts]

i called them about fixing my old 1501d and they said that they wouldnt fix it, just take it as a trade for a new amp. that was like 2 years ago.

They wouldn't?? Hmm weird. Maybe their rules have changed since then. But I was talkin some yrs ago. Back then it was 66 bux any amp for repair. I don't understand why they wouldn't fix one of their own amps when your trying to help them stay in business and they in turn help you out...