Ampere Audio 8k

[mnhiphop101]

This amp came in with a blown ps. I replaced the emitter follower pairs and have good drive on all banks. After installing the fets i powered it up and something popped but I can't figure out what it was and now when I apply power the amp turns on without the remote connected and the fets on one of the banks is heating up. When i pull the fets out of that bank the amp powers up fine and the voltages and drive signal on that bank are normal.

 

[Perry Babin]

Do all of the FETs check to be OK?

Did you check the drive with a loading capacitor on all banks?

 

[mnhiphop101]

All of the fets are new.

No i didn't use loading capacitors. Is there a section in the guide on this?

 

[mnhiphop101]

why would it be turning on before the remote is applied?

 

[Perry Babin]

Tech tips 9, item #23.

I'd be more concerned with the drive at this point. Turning on without remote is likely a shorted transistor in the remote circuit if the supply voltages on the driver IC are good.

 

[mnhiphop101]

Ok i got the drive issue figured out. It was a shorted transformer. Now I just need to figure out why its turning on without the remote hooked up.

 

[Perry Babin]

If you need help and no one offers any suggestions, post photos of the PS driver board.

 

[mnhiphop101]

Here's a pic of the ps driver card.

 

[Perry Babin]

It's likely that either Q8 or Q7 is shorted.

 

[mnhiphop101]

Ok ill try replacing those but it happens even when the driver card is out of the board.

 

[Perry Babin]

How do you define 'turning on'? Without the driver board, there is nothing to drive the FETs so there is no power.

 

[mnhiphop101]

You make a good point. I don't know why I was thinking that.