Home amplifier blowing fuse - HELP!

[eKretz]

You could be right, I don't have any older stuff to compare to. All my boards with anything gluing the caps use either white or clear goop (most seem to be hot glue type stuff). That pic's residue sure does look nasty to me though. Maybe it has just discolored with age. I can't get a clear look at whether it looks deliberately applied as I'm using a phone to view and the pics are pretty small. I actually thought the board and link DID look discolored/corroded by what I saw on the phone screen, but if you are viewing on a computer I think you have a much clearer/larger view.

 

[KrisBlueNZ]

It looks to me like the end of the link that's within the goop is discoloured (dark brown, a darker shade than the goop) but it's not corroded in any way. I think that's just the goop itself.

The main reason I think it's goop not leakage is that it seems to have formed a web around the edges of the bottoms of the capacitors, between the board and the capacitors, part way up. That means that it's filling the gap around the curved part of the base of the cap, which implies that it's been put there from the outside. Maybe with a brush.

 

[eKretz]

Ahh, I can't see that on the little screen. Now that I have looked on the computer I see what you mean.

 

[WhiteFro]

Ok this is the closest thing to a schematic I could find for my amp The Aura VA50 by B&W.

attached...

 

[WhiteFro]

Can anyone give me an explanation of what is going on in the above circuit?? I have studied some electronics but it was a long time ago, trying to get back into it so need some help.

 

[KrisBlueNZ]

The +A and -A outputs are the main positive and negative rails coming out of this power supply. The -C output is an auxiliary negative voltage output. The right hand part looks like it's supposed to be a dual regulator producing +B and -B rails but it's drawn wrong.

 

[eKretz]

Start checking your voltages from the power supply onwards. Kris has given you a hint where to start. Check your schematic to see what the voltages should be (I haven't looked, you may need to use math) and check what they are.