Olimex Support Forum

OLinuXino Android / Linux boards and System On Modules => iMX233 => Topic started by: Dave on November 11, 2013, 05:21:09 pm

Title: MAXI Revision C very hot?
Post by: Dave on November 11, 2013, 05:21:09 pm
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?  :o


Thanks,
Dave
Title: Re: MAXI Revision C very hot?
Post by: aquarat on November 17, 2013, 08:51:15 pm
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.
Title: Re: MAXI Revision C very hot?
Post by: Kean on November 19, 2013, 04:11:19 pm
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
Title: Re: MAXI Revision C very hot?
Post by: Dave on November 22, 2013, 05:28:03 am
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