krumelur Posted May 6, 2005 Report Share Posted May 6, 2005 Help needed! Quick fix preferably ;).. probably faulty cause my pcb is a real mess.. not to mention my soldering. I could use some advice to pinpoint the problem. Anyway, here it goes:measuring pin 1 to 12 (power, ground), where Im supposed to get 5V I get 0,5-0,3V, same for the whole board so there must be something wrong with the power supply to the board, early in the chain. Ive tried two different power adaptors - one 9V with 200mA and one 8V with <3A.Measuring at J1 gives a proper result, and measuring with one pin of the multimeter at J1 and the other at various places throughout all modules (only where its supposed to though) gives a good reading of around 5V.IC3 (7805) gets very hot really quick though, so I am suspecting a short somewhere, but I could use some help pinpointing the exact location. I cant find it anywhere. I am quite sure I have all the correct components with proper values and anything - the ceramic caps are suspicious though cause they dont look anything like those on the pictures on the net - can the problem have anything to do with these? I dont know much about electronics really, just following the plans and instructions so any help whatsoever is welcome :)Btw. my core is built from the plans on www.ucapps.de.peace out fellow DIY-ers! Quote Link to comment Share on other sites More sharing options...
etko Posted May 6, 2005 Report Share Posted May 6, 2005 This will maybe sound dull, but check it!Did you isolated cristal(oscilator). I've expirienced the same problem becouse of unisolated cristal. Quote Link to comment Share on other sites More sharing options...
moebius Posted May 6, 2005 Report Share Posted May 6, 2005 Some pictures might help--- Â ::)I'm tired, so my logic might fail here... Â ceramic caps shouldn't be a problem here, ceramics come in different shapes and sizes (and are (not so) easily only to be mistaken for tantalums, that are polarized and usually have much larger capacitances).uh, AC or DC supplies? Gnd shorted to +5v thru some resistor connection, causing excessive current consumption (heating the regulator) and pulling PIC Gnd pin up?Bye, Moebius Quote Link to comment Share on other sites More sharing options...
krumelur Posted May 11, 2005 Author Report Share Posted May 11, 2005 ill try to supply you with some more information.. just been too involved with some other stuff.. Quote Link to comment Share on other sites More sharing options...
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