# Planet Audio BB150.4, issue. Guts shots.



## schmiddr2 (Aug 10, 2009)

I have 12v at the amp. It will work for one minute then goes into protection for 10 minutes or so then comes back on for one minute and so on. I have disconnected everything from the amp except for power and it is in protect mode.

Anyone see any issues within the guts pictures or have any idea why I'm having this issue?


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## schmiddr2 (Aug 10, 2009)

I have a feeling I was blasting tunes too loud, but I really never heard clipping.

I assume it is having internal issues and either has to be repaired or sold as broken. Wish it was one little part, but I don't have the skillz to find it anyway.


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## underdog (Jul 5, 2011)

In that last picture.
Left side at the bottom of that row in the vetical dark area.
There is a nasty looking area in the circut board.


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## schmiddr2 (Aug 10, 2009)

Indeed, and if you expand the picture you will see it's on all the pins that are in rows like that. They are pins that connect the top circuit board to the main board. But what caused it to look like that? It looks like bad solder or soldering to me, but I don't know.


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## envisionelec (Dec 14, 2005)

That's just harmless flux residue.

These amps with the "clips" that hold the transistors against the heatsink are known for stressing the leads causing them to fracture. The amp might work until it warms up or randomly go into protection.

The fix is to remove the board, inspect each transistor's leads and replace the fractured ones. When you replace them, kink the leads out slightly so as to put a little "knee" in the lead that can absorb some of the fracture-causing energy. The problem is that they solder the transistors so close to the board, that you can't pull them out enough to kink the leads, so you have the problem occur again as the other ones fracture. The best fix is to replace everything and kink all of them and the problem may never occur again - but you're looking at $150-200 in parts if they're the really high dollar FETs.


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## schmiddr2 (Aug 10, 2009)

Interesting! Thanks

How do I take the clips off to get the to the transistors? I also want to look at the back of the board.


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## schmiddr2 (Aug 10, 2009)

Got the clips off. That was very difficult. I don't see any broken legs. Now I need to determine if any of them measure differently without removing them?

Going by Babins guide on bcae1.com, "When checking transistors (bipolar or FET) with your meter set to ohms, you should not read anything near 0 ohms when the probes are touched to the terminals of any individual transistor in any configuration. If any are shorted (~0 ohms between any 2 legs of any individual transistor), they will likely be shorted from leg 2 to leg 3 but you should check 1-2, 1-3 and 2-3.", I measured more than zero on all legs of every transistor.

More pics:


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## schmiddr2 (Aug 10, 2009)

Geez, what to do with this thing. Wonder what a good asking price is for this amp. It's probably not worth the cost of shipping and repair. Could just put it back in the box and set it in the closet until one day I find it again just to throw it away.


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