Audiobahn A2300HCX - Need Help!

[Perry Babin]

That means that no rail voltage is being produced.

What's the DC voltage on leg one of the power supply FETs? They are the smaller transistors clamped to the heatsink on the end of the amp with the power/ground terminals (Q22P, Q23P...). Check them on both sides.

 

[piersm2]

there are points on the circuit board where the number like Q22P is. Do i have to measure the the legs on the transistor or can i just measure the solder point on the board where the number is?

 

[piersm2]

which leg is leg one?

 

[Perry Babin]

Those designations (Q22P...) aren't references for those points. They refer to the transistors.

 

[piersm2]

Do i put the black probe on the ground terminal of the speaker output for these measurements too?

 

[Perry Babin]

Place the black probe on the same point you did when you measured the DC voltage on the 494.

 

[piersm2]

I placed the black probe on the ground terminal for the amp. Will that work?

 

[Perry Babin]

Yes

 

[piersm2]

The first leg would be the one to the far left when i am looking at it correct?

 

[Perry Babin]

Did you look at the image I posted?

 

[piersm2]

Yes I was just making sure that the diagram was as if I was looking at them straight on or if it was as if I was looking from the back

 

[piersm2]

Here are the reading that i got:

Q11P-13.75v
Q12P-14.09v
Q13P-14.09v
Q14P-14.09v
Q15P-14.09v
Q16P-14.09v
Q17P-14.09v
Q18P-14.08v
Q19P-14.05v
Q20P-13.96v
Q21P-6.9v
Q22P-14.3v
Q23P-13.87v
Q24P-14.03v
Q25P-14.14v
Q26P-7.49v
Q27P-7.1v
Q28P-13.3v
Q29P-6.92v
Q30P-14.1v

 

[Perry Babin]

If that's the voltage on leg 1 and the voltage on leg 3 is ~0v, they all need to be replaced.

Have you checked the output transistor to see if any are shorted?

 

[piersm2]

Those are the bigger transistors than the ones i just measured correct? Would I just use the resistance setting on the multimeter to check those out? From leg 1 to 3? Also, the transistors have a white substance that is behind them where they attach to the heatsink. How do I go about replacing them? Sorry for all of the questions. I am new to electronics repair. I greatly appreciate you taking the time to help me out.