Sound Stream Class A 5.2

[SlappinM30]

I bought this amp a few years ago as part of a package deal. I hooked it up before purchase and it worked, but as soon as I tried to use it for real it popped 4 mosfets on the input side. Included are some pics of the board and of the blow mosfet, does anyone know a good place to buy them? This is a gorgeous amp and I would love to get it going again.

[Perry Babin]

Digi-key has them.

You also need to check the gate resistors and the driver transistors that drive those FETs.

Did you check the output transistors to see if any were shorted?

Did you check the rectifiers?

[SlappinM30]

In the first pick are those the diver transistors, and in the second pic are those the gate resistors? What I think are the gate resistors are also a little burnt looking but I can't seem to find them on the net to find out what they are.

[Perry Babin]

The driver transistors are Q29, Q33, Q34 and Q37. The PNP drivers (the black ones in each pair) are the ones that most commonly fail.

The gate resistors are orange, orange, gold, gold and should read 3.3 ohms ±5%. You won't be able to check them until you remove the failed power supply FETs.

[SlappinM30]

Ok so

Q29 seems to run at normal temp/
Q33 looks blown
Q34 gets hot when powered on
Q37 look blown
Any ideas on where to buy these parts?

Thank you for the help

[Perry Babin]

Have you removed the failed power supply FETs?

[SlappinM30]

No not yet but I can do that now.

Edit: done

[Perry Babin]

Check the resistors.

Do the drivers still get hot?

[SlappinM30]

I have run real quick , but I will check those and power it up as soon as I get back.

[SlappinM30]

I found a resistor that may be a problem, it is the one closest to the edge of the board. It seems to have a hot spot on one of the gold strips as shown in the picture. To power it up I should re mount the board to the heat sink right?