Bad MAX9814 mic boards

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Anthony1964
 
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Bad MAX9814 mic boards

Post by Anthony1964 »

Hello,

I had purchased six MAX9814 (PRODUCT ID: 1713) and found that two did not work properly.

I inspected the boards with a jewelers loop and discovered that the two bad boards had solder bridges on some of the IC's pads.

Four were ordered on 10/30/2014, Order Confirmation No: 618084-2772727742.

And two were ordered on 11/10/2014, Order Confirmation No: 625685-4425865657.

How do I go about returning these two faulty boards?

Thanks,
Anthony

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Franklin97355
 
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Re: Bad MAX9814 mic boards

Post by Franklin97355 »

Could you post clear, detailed pictures of both sides of your boards?

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Anthony1964
 
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Re: Bad MAX9814 mic boards

Post by Anthony1964 »

Here are the photos.

You can see clearly that there are solder bridges across some of the IC's contacts

P.S. Your "Add The File" feature would not allow me to add the fourth file. It says 3 attachments is the maximum.
Attachments
IMG_0309.JPG
IMG_0309.JPG (928.59 KiB) Viewed 529 times
IMG_0311.JPG
IMG_0311.JPG (893.18 KiB) Viewed 529 times
IMG_0310.JPG
IMG_0310.JPG (894.35 KiB) Viewed 529 times

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Franklin97355
 
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Re: Bad MAX9814 mic boards

Post by Franklin97355 »

Thanks, several of your solder joints could use some more work. Take a look at this Soldering Guide for help.

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Anthony1964
 
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Re: Bad MAX9814 mic boards

Post by Anthony1964 »

I highly recommend that Adafruit check all their MAX9814 boards.

A 33% (2 out of 6) defect rate is a little high.

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Anthony1964
 
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Re: Bad MAX9814 mic boards

Post by Anthony1964 »

Why am I tasked with fixing your product that I purchased from you????

Shouldn't you just give me a refund or store credit for these two defective boards???

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adafruit_support_mike
 
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Re: Bad MAX9814 mic boards

Post by adafruit_support_mike »

Apparently Franklin was looking at the pin header joints.

There are indeed solder bridges across the pins of the MAX9814 chips in the photos you've posted:

- The bridge in IMG_0309.jpg is between the Gain Select pin and a non-connected pin. It should have no effect on the chip's performance.

- The bridge in IMG_0311.jpg is between the AGC threshold control and microphone bias pins. That particular short disables the AGC system, but leaves the amp generally functional.

- The bridge in IMG_0310.jpg is between the AGC attack threshold pin and the shutdown pin (which happens to be wired to VCC on the breakout). That would cause the AGC to kick in and out very quickly, but again would leave the amp generally functional.

I'll pass this information along to our fabrication and testing teams. It's possible that the testing jig for that product needs to be updated.

In the meantime, please send a note to [email protected] with a link to this thread and the folks there will get some replacement MAX9814 breakouts headed your way.

If you're comfortable with a soldering iron, you can get rid of all three solder bridges by dipping a piece of phone wire (24 gauge) in flux, holding it against the pins that are bridged, and heating the wire with a soldering iron. That's completely irrelevant to the replacements you'll receive, but it does give you some additional amps if you want to invest the effort.

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Franklin97355
 
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Re: Bad MAX9814 mic boards

Post by Franklin97355 »

Bill is correct, I was looking at the pin headers you soldered on not the chip itself. Sorry for any confusion.

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