AVR-Chat

On Fri, 4 Feb 2005 08:26:43 -0300, Javier Fiasche <jfiasche@tutopia.com>  
wrote:

> Well Guys i finally mannaged to make my Atmega32 run well. The thing was  
> taht the PCB manufacturer sended me a bad PCB, where net GND was split  
> and not connected to the uC. It wasnt a design problem, just a  
> manufacturing one. I wasnt able to find it before because the splited  
> part was under the TQFP atmega32.Thanks you all for the help. I found  
> the problem beacuse one of you suggested connecting all VCC and GND  
> pins, and just connecting GND , it started to run.In the future, i'll  
> make sure that the PCB is ok, and i wopnt trust in manufacturers any  
> more!!!!!!GND is something to have in mind  :-) Well regards and thanks  
> a lot to you all Javier


If you simply measure the supply pins with a digital voltmeter as i  
suggested you will easily find such faults. You must connect the gnd of  
the meter to the supply gnd.

Visual inspection of each PCB is a good idea, especially in areas where  
there will be no access later. Electrical testing is too much effort for  
me. You can never be 100% sure there are no breaks, no matter if you have  
your boards made or make them yourself. inspecting against a bright light  
source shows some faults you don't see normally (but it only works if  
there is no copper on the other side, on that spot), it also shows holes  
which are not drilled.

ST