Identify mosfet

[Electroman55]

Hey everyone, just looking for some information on a power mosfet. It's a Motorola brand with the numbers mta30n06e stamped onto it. Any help with data sheets, suitable replacement info or sources of parts would help me out huge. The only replacements I can find are over 10 dollars each, and since I need 12 I'm hoping there's a cheaper option lol. Thanks in advance .

 

[Electroman55]

http://item.mobileweb.ebay.com/viewitem?index=0&sbk=1&nav=SEARCH&itemId=170960567700

Think these might work for me but I'm not sure.

 

[(*steve*)]

It depends what you're using it for and what the important specs are.

The device is an isolated tab (plastic?) TO-220 N Channel mosfet with 60V V(br)dss, Rds(on) of 28 milliohms, Id of 30A, and Pd of 50W

 

[Electroman55]

They're for a car amp that my friend blew up and gave to me. I thought I would attempt to repair it. Its an old alpine mrv-1505. 2 of the power supply fets are burnt I noticed and the corresponding gate resistors aren't ohming out properly. Also a cap literally fell off the board when i touched it. Deteriorated solder joints. Cap was in spec so i reinstalled it. The strange thing is the amp still powers up and actually produces sound for a short while, then kicks into protect.

 

[Electroman55]

I'd post up pics but I can't figure out how on my phone. Also please be gentle lol I'm far from pro, and despite hrs and hrs of research, I can't seem to find the information that I need. I'm not 100% sure of the values I should be comparing. I also can't find anything about these Motorola mosfets :/. Help! Lol

 

[(*steve*)]

Are these mosfets connected to a heatsink? Are there any inductors (coils of wire or transformers) very close nearby?

What do you mean by the resistors not ohming out properly? What do you expect, what are they marked as, and what do you get?

Also, are the mosfets short circuited between source and drain? And is there any conductance between gate and either source or drain?

 

[Electroman55]

Heat sink yes. And yeah there's a rather large inductor on either side as well as a transformer. Ill have better answers about the resistors later (i havent checked the values yet) but it looks like there's 2 in parallel on each mosfet gate. Each pair meters out at 10 ohms and 123 ohms except the particular pair for the fet that actually burnt. That one meters out at 70 ohms or so. But the other one came out fine at 10 ohms. I'm assuming its a switching power supply I'm dealing with here?

 

[Electroman55]

I haven't noticed any shorts since I removed the 2 damaged fets. I was planning on replacing them all on that side of the board because theyre paralleled up. Ill check the conductance between the gates and drains. I removed a shorted fet and a burnt one and haven't noticed any more shorts, but ill get busy with the meter when I get home and get some better answers for you.