brutus 1600w

[timwebb]

ok i let a friend use my amp hooked up and blew it, what can i use as an replacement for WFP50N06

 

[Perry Babin]

There are quite a few that should work. What is the value of the gate resistors?

Do you have any FETs or are you going to have to order them?

 

[timwebb]

the resistors are 400ohm.i have some new irf 3205 that i was thinking might work
im going order some more just got laid off so tryin to make this my main job for now.

 

[Perry Babin]

It's not likely that the gate resistors for the power supply FETs are 400 ohms. It's more likely that they are 47 ohms. Re-check them.

 

[timwebb]

yeah my bad will irf 3205 work?

 

[Perry Babin]

I think the 3205s will be OK.

If you need this income to pay bills, I'd suggest that you not order from ebay. You may pay more than the ebay price but you know you're getting good quality parts.

 

[timwebb]

thanks man

 

[timwebb]

ok i changed all the fets and gate resistors but the same one keeps on blowing,what am i missing?

 

[brandes.cm]

Did any of the gate resistors open or the drive transistors?

 

[FireII]

ok i changed all the fets and gate resistors but the same one keeps on blowing,what am i missing?

Are you sure that the insulator is in good condition? Also, when is it blowing?(when powered on, when driven hard?)

 

[timwebb]

when i power it on i can hear it fry then the amp shuts off it powers up fine when its out

 

[FireII]

when i power it on i can hear it fry then the amp shuts off it powers up fine when its out

Have you checked the drive signal? Also did you check the insulator to make sure that the transistor wasn't grounding to the sink?

 

[timwebb]

here's what i got from the driver the first one is the first two drivers the second one is the last two.

 

[Perry Babin]

Do you possibly have an intermittent connection in the circuit feeding the gate leg of the FET that keeps failing?

Are the gate resistors all within tolerance?

For the waveforms...
What were the vertical amp and timebase settings?

Did you set the trace precisely on the reference line before touching the probe to the test point on the board?

Is your scope grounded to the same point as the amplifier?

 

[timwebb]

yeah i set everything as best i could i have to re calibrate my scope its old and its starting to give distorted pictures the two on the far left is whats linked to the one that keeps blowing.i was gonna pull that part.

 

[timwebb]

what a good replacement for the C3227 tansistor

 

[Perry Babin]

I don't have an exact cross but I've used the BD139 and BD140 as substitute power supply drivers without any problems. The leads are a bit larger than the transistors in that amp but they should fit. The BD140 would be the sub for the C3227.

Are you sure that it's defective? The PNP is the one that generally fails.

Did you try removing the FET that keeps failing to see if any others would fail?

 

[timwebb]

ok i i pulled the first three on the right and last three on the left now it powers up and idles fine

 

[Perry Babin]

Is that a gate resistor that appears to be out of the board on one end?

If so, were all of the gate resistors soldered in place and intact when you had all of the FETs in the circuit?

Are any of the FETs you pulled defective?

 

[timwebb]

im pulling those now they are 47ohms but they read 44-45ohms