What's up with the Blackstar Fly 3 Speaker circuit board ?

[George Moore]

  The reason I ask is that apparently there's a stereo hookup using the Fly 103 ext. speaker, since I have a blown combo amp [speakers probably good] the prospect of getting a working B.S. fly combo and using this speaker for the other side of stereo intri .gued me, but the circuit board on the speaker has a circuit board with a round silver chip and a number of other parts there...doesn't look simple and raises the question...what's going on in here??? Perhaps information from the speaker is fed back to the amp or DSP circuit.
Curious and just guessing./
 
 

[anotherjim]

The 103 extension is powered by its own amp as far as I can tell. Basically the Fly3 has some stereo capability, but only a mono amp of its own. It doesn't appear to be a good idea to drive another speaker directly off the Fly3.

[George Moore]

  thanks anotherjim !
  It was donated as is. Seems to have an F1 [fuse 1 probably], that was open, I closed it with a wire hoping an LED indicator or other sign of life would be emitted...nothing.
  I figure since it is clean as the day after it was unboxxed, an AC or otherwise wrong power supply fried the guts, the best parts, the main interest I'd have had in it.
  Another case of a ~brand new item, ready for discard.

[George Moore]

  Well it has a little speaker must be good for something, it's in a box already, but Idle-ey curious as to what the little board on the speaker is designed for.
  My exp. has been that fixing a pilot lamp circuit often restores the audio circuit...I'll probably search for info such as schematic when I get time to, as this portion of the circuit can be partially seen and therefore posibly worked with, the rest is otherwise useless, SMD...

[vigilante397]

  My exp. has been that fixing a pilot lamp circuit often restores the audio circuit

Really? I have not had such experiences. Unless by pilot lamp circuit you mean power supply, in which case I would agree.

[George Moore]

  I figure most likely a reverse voltage or AC happened to it, perhaps I'll take another look.

[mgalicki]

I have a Fly that I believe I fried the circuit board on the speaker. If you feel yours is good, would you sell it to me?
Thank you.

[Rob Strand]

I have a Fly that I believe I fried the circuit board on the speaker. If you feel yours is good, would you sell it to me?
Thank you.

The amp chip is fried for sure.   There's a schematic on-line. 
The IC is PAM8304 (3W class D amplifier).

There's a chance the speaker is fried as well you would need to test it.

[mgalicki]

Tested speaker & it works! so the IC PAM8304 might be the culpret? I think I can order one on line? Does it matter which way it goes in, is there polarity?

[Rob Strand]

Tested speaker & it works! so the IC PAM8304 might be the culpret? I think I can order one on line? Does it matter which way it goes in, is there polarity?

Yes, very important to get right.

You need to get the datasheet or at least the on-line schematic.  Normally there's a pin 1 marking on the IC.  When you fry chips it's hard to see pin 1 but you can deduce it easily by looking at which IC pins on the PCB wire to the speaker and which pins are wired to the power.

[mgalicki]

I was able to install the new chip, but no go. Still no sound. Wish I could just buy the complete board from blackstar but they won't answer...

[Rob Strand]

The support from companies sucks these days.

Some things to check would be that the power supply is still working and that the output inductors have not shorted.

The thing that *caused* the chip to blow could be bad caps on the power supply for example.