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slipton  
#1 Posted : Monday, June 11, 2012 2:59:39 AM(UTC)
slipton

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Hi,
My Buffalo II recently stopped working. After some narrowing down, I have found a short from VD to ground. After desoldering C12, C15, L1, there is still a short across a lot of SMD caps near the Buffalo chip. What do the experts say? I expect that my Buffalo recieved ESD and died, but obviously don't want to shell out for a new one if I don't have to.

Also, in the event of a toasted Buffalo, what is the recommended replacement path? I have access to SMD soldering equipment and can probably replace the Sabre32 without killing it.

BTW, I have checked the Placid supply and it is A OK. I found a few other threads, and would just like to confirm that my chip itself is fried. Thanks ahead of time for the help,
Saul L.
Russ White  
#2 Posted : Monday, June 11, 2012 3:16:19 AM(UTC)
Russ White

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Short from D to GND sound more like a dead VREG than a dead chip. But t could be either.

I would try removing all of the ferrites one by one and see if you still have the short.

slipton  
#3 Posted : Monday, June 11, 2012 4:15:38 AM(UTC)
slipton

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Hi Russ,
I had removed ferrites L6, L7, L8, and then discovered that L8 fixed the short. With L8 still removed and L1 removed, I now do not measure a short at VD, but at the capacitors that I assume are farther down the line from VD. Thanks,
Saul
slipton  
#4 Posted : Monday, June 11, 2012 6:19:20 PM(UTC)
slipton

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OK, I remeasured my board just to be sure about my results. Initially, with all L's on board but the AVCC board detached, I measure a short from VDD to GND. When I remove L1, the short is gone from VDD, but present on C15, C12, C1-8. I do not have the AVCC module with me at the moment, so I cannot check to see if it too has a problem. I am fairly sure that when I checked it last night it was fine. What do you think?
Saul
slipton  
#5 Posted : Monday, June 11, 2012 7:51:49 PM(UTC)
slipton

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Location: Athens ga

More measurements... I disconnected L1 and powered up the VDD regulator, it measures 1.22V on the nose, exactly as it should.
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