MAXI Revision C very hot?

[Dave]

Hi all,

I'm running a MAXI Revision C with a 12V/1000mA supply in open air.  I noticed that all the chips on the board are pretty warm but that was nothing compared to the power supply section.  I literally burned my finger on the top of C68!  Is this normal? 


Thanks,
Dave

[aquarat]

I've got an imx233 MAXI which is running quite a few peripherals (USB wifi dongle and USB 3G modem) as well as a GPS receiver (from adafruit) and a Java application... and I can barely feel any heat on it. The SMSC USB/LAN chip is probably the warmest, but it's warm rather than hot.

[Kean]

Dave,
In normal operation, just like aquarat, I found them to run quite cool.
How are you connecting the 12V?  Via the DC input jack?
The reason I ask is that I ran some Maxi's off 5V coming from the GPIO connector, and I had to disable the DC/DC converter (pin 7 to GND) - otherwise it would boost the 5V bus back to the DC input, and generate a higher voltage than C68 could handle - making it very hot just as you describe.
Check some voltage around U5 to make sure it all looks normal.
Kean

[Dave]

Thanks for the replies.  I think I found the root of the problem.  Unfortunately, D3 had to let out the magic smoke in the process...    It turns out that the "12V" supply was putting out more like 16V and I think I got enough of a surge when I plugged in to pop D3.  Never trust a wall wart!

Mine said "12V" but I the forgot to include the notation that it's 12 base 14!   

Hopefully nothing else is damaged and I can just replace D3 and use a 5V (base 10!) supply.


Thanks again,
Dave