Crunch p.zone 1500.1

[treepile]

Hi all, I got a crunch amp that I got from a buddy. The potentiometer for the low pass was damaged, and replaced. However, there was no heatsink compound used in feasible. At first amp worked, then shut off, now it blows all 4 fuses when power is connected. Any guidelines to checking mosfets, and where to get the parts? Thanks so much

 

[Perry Babin]

Does it blow fuses with only B+ and ground connected?

Or does it only blow the fuse after remote voltage is applied?

 

[treepile]

Crunch

When remote is applied

 

[treepile]

When remote voltage is applied

 

[Perry Babin]

That typically means that one or more of the output transistors has failed. It will likely read a direct short between legs 2 and 3. The output transistors are the larger transistors clamped to the heatsink.

 

[treepile]

Ok, thanks, what about the mosfets, from outside to outside, they go down to zero

 

[Perry Babin]

'go down to zero' what (what are you measuring, ohms, volts...).

 

[treepile]

Dioid mode, all 4 have same reading

 

[Perry Babin]

The only components that should/may read 0.000 on diode check are the rectifiers. The FETs should not read 0.000.

 

[treepile]

Thank you for ur valuable time Mr Perry, pretty sure I need to replace output transistors & mosfets. Where would be good place to get? And will numbers on parts be good for I.d.?

 

[Perry Babin]

If you're going to blindly replace parts without proper troubleshooting, you don't need my help.

 

[treepile]

Well excuse me sir, I thought that would be the problem