LM3886 amp board sparks and smoke

[DionG]

Hi,
Today i powered up my LM3886 amp board as i have done before but this time thing went wrong. Its powering a subwoofer but this combination of psu, amp board, imput and sub have been used before with sucess.

today the sub is in a new box i built myself. i powered it up without any input and everything as well so shut it down and turned it back on with music input from my iphone (as have doen before) but this time things went wrong.
after about 1/2 a second smoke and sparks fly from an amp chip. the board being used is: (paralelle btl configuration)

300W Mono LM3886 X 4 + NE5532 POWER AMPLIFIER KIT | eBay

The chip that blew is the 3rd from the left (in the main pic) and pin 4 (what i believe to be V-)of this chip is completely burned out.
I checked the psu afterward and it is working fine giving the +- 35 V it should.

If anyone can help me or have any ideas it would be much appreciated.
the rest of the board looks fine so i can solder a new chip in but will it just happen again is the question?

thanks
Dion

[AndrewT]

probably !
We get more queries on problem multi-chipamp assemblies than on almost any other chipamp topic.

[DionG]

thanks haha but no ideas why? i mean its worked before is exactly the same setup except a sub box change..

[Professor]

This is a PA100 in bridge configuration?

[AndrewT]

without a schematic and a detailed closeup of both sides of the unpopulated PCB, we have no hope of easily helping you to sort your broken amplifier.

Go back to your supplier and ask for customer service.

This is a PA100 in bridge configuration?

which makes it a bpa200. I wonder where 300W comes from?

[Professor]

Originally Posted by AndrewT

without a schematic and a detailed closeup of both sides of the unpopulated PCB, we have no hope of easily helping you to sort your broken amplifier.

Go back to your supplier and ask for customer service.which makes it a bpa200. I wonder where 300W comes from?

You suggest him to call in China?

[DionG]

close up pics of unpopulated pcb
300W Mono LM3886 X 4 + NE5532 PCB Double Side Board | eBay

[AndrewT]

yes.

If one takes the risk of buying from China direct, then one must also take the risk that if problems become evident then the buyer is almost alone. Paypal and Ebay may be able to refund money in event of fraud, but kits that work and then fail are outside what they and us can sort.

[AndrewT]

Originally Posted by DionG

close up pics of unpopulated pcb

from those you can reverse engineer the schematic.
Then add on device names/types.
Finally determine normal operation and possibly guess at what is wrong with the design and/or assembly.

[DionG]

.... so is it work replaceing the chip do you think?