Phoenix Gold XS4600 blown trace

[jrodajames]

I Purchased a Xs4600 from Ebay for repair and initially it looked good however upon further inspection I discovered the trace from the negative side of C31 has been destroyed. I can repair by repairing connections but I need to know where to make those connections. Can anyone help with information on what C31 top trace connects to?

 

[Perry Babin]

You'll have to remove the cap that it goes under as a start. You should be able to see under the other components.

 

[jrodajames]

I removed the cap and there is a wide copper strip that has been trimmed off. I cannot determine where it was attached to other components. If you look closely at the picture you can see where the copper was trimmed off under the cap.

 

[Perry Babin]

Photo with cap removed?

 

[jrodajames]

I'm away from home for a few days, I'll post it as soon as I return home. Thanks

 

[jrodajames]

 

[Perry Babin]

What's the resistance from that burned trace (near the cap) to the non-bridging terminals on the speaker terminal block?

 

[jrodajames]

Across all non-bridging terminals resistance is 0.1, which is essentially the same as touching my leads together.

 

[Perry Babin]

Is it the same from those terminals to the part of the burned trace near the cap?

 

[jrodajames]

Yes, sorry that's what I intended to say.

 

[Perry Babin]

Have you tried to play the amp?

 

[jrodajames]

I did, it blows both fuses as soon as I connect power. I connected the positive first and as soon as the negative touches it pops both fuses.

 

[Perry Babin]

Measure the resistance from the gate to the source for all of the PS FETs. Post the resistances. If all read the same, you only need to post one number. If you have several that read low, post all of the resistances and the corresponding circuit board designations for the FETs.

 

[jrodajames]

Q10-Q11 and Q12 are all 11.99
Q7=62.1 Q8=2.0 Q9=62.2

 

[Perry Babin]

Remove Q8 and recheck.

 

[jrodajames]

With Q8 removed

Q10,Q11, and Q12 are OL
Q7=17.17
Q9=17.14
Removed Q8=2.2

 

[Perry Babin]

There may be a bad driver.

Do you know how to check transistors?

 

[jrodajames]

Check for voltage drop across pins?

 

[Perry Babin]

I'm not sure what you're asking but on diode-check, that's basically what you're doing.

There are 4 transistors (Q2-Q5?) connected between the output pins of the SG3525 and the gate resistors of the PS FETs. Pull those 4 transistors and check them.

 

[jrodajames]

Q2-Q5 are all testing good