2sk3662 substitutes?

[shagone]

i have an alpine mrpf250 with all 4 power supply fets blown out bad with black soot all over! i managed to read k3662 on one of the 4 so i assume that all 4 were toshiba 2sk3662?

has anyone had luck with other fets in place of these? i have 4 new irfz44 fets, would these be ok without changing any other components? what else could i use? or should i just order a few of the 2sk3662? i'll be fixing more of the same amps in the near future but i was wondering if a beefier fet would help much? the 2sk3662 shows 60v 35A.

Thanks for any advice for a "newb" of sorts. i'm a 12 year tech but new at amp repair.

[1moreamp]

You can beef up the fet without much issue, unless your drivers are not meant for the load and you might just have to change the gate resistor to make the turn on/ turn-off work correctly. the Z-44's are a fair sub for a 35 map rated fet that was there.
I would be checking your gate drivers as from the sounds of it they are smoked also. If you don't it will fail on start up the first time most probably.

Good luck

[turbopilot]

I lift this old tread instead of creating a new.

I have almost the same problem as shagone, I tried to mail him but because I haven´t made any posts yet (new member) I can´t use the mail function.

Anyway I just want to know if it worked to just replace the blown K3662 with new 2SK3662 ?

Very thankful for answers!
/Johan

[shagone]

Originally posted by turbopilot
I lift this old tread instead of creating a new.

I have almost the same problem as shagone, I tried to mail him but because I haven´t made any posts yet (new member) I can´t use the mail function.

Anyway I just want to know if it worked to just replace the blown K3662 with new 2SK3662 ?

Very thankful for answers!
/Johan

i used 4 IRFZ44N with 4 new 100 ohm gate drive resistors (some of mine were burned slightly and out of tolerance). the amp worked fine after that.

the original 2SK3662 should work fine as long as you check your gate drive resistors and your drive transitors. i was lucky and mine survived, many times they don't.

[turbopilot]

Thanks for your help!

I attached a photo of my amp that I bought on eBay and was stated to be in great condition
The first notice I did was that the previous owner had put 2x35A fuses instead of 2x15A that it should have been...

Where are those gate drive resistors located?

[turbopilot]

When I removed the heatsink and looked on "the solder side" I found a much bigger problem, the circuit board is cracked

Right now I´m not happy at the person he sold me this ****, will demand all money back.

I suppose this is nothing worth to try repair or? many of the circuit lines are cut of.

[Perry Babin]

I'd suggest trying to get a refund. If he refunds your money and tells you to keep the amp, then you can try to repair it.

If he won't refund your money, it can probably be repaired but it may take quite a bit of time.

[Smartass365]

I ended up clipping the gate lead on the 3662's so I could power the amp up and see what I had coming out of the collector of the driver transistors.

What kind of voltage should I be getting at the gate of the 3662s? And has anyone been able to read the values on the tiny little gate resistors?

[nacorona]

*bump*

I just picked up this same amp.. the 3662's at the extreme end are visibly blown.. no apparent damage elsewhere. Knowing what values I should see would be great if anyone knows...