--- microsoftwarecontrol wrote: > designed by protell99se, > made double-sided pcb by myself, > but my led dot mitrix diver didn't work > as hope. It seems has interfering > from some where. > All right... > before, one wires been manually solded, works > perfectly. So, the pcb will bring more electrical > interference? How to deal with > it ? Add C and L, at where? > Hmmmm there seems to be something missing here. > Driving signal come from a 16f876a, with 100om > protecting res. > Ok... Now here is the questions that come to mind: 1) What circuit are you using? 2) Is this directly driven by the PIC? 3) Are you multiplexing the LED's? 4) What did you do for eliminating power supply noise etc? 5) Is the PIC properly decoupled? 6) Is the IC (if any) driving the LED's properly decoupled. 7) What is it doing? 8) What should it be doing? Off the top of my head I can't tell you. Your problem isn't clearly defined in what is going wrong, and what it should be doing. Your circuit is not defined either, nor is your method of operating the LED's. I am sure the kind people on the PIC list will help you, if you help them help you. Take a breath and be calm, think what is going on and what it should be doing. Let us know what is going on so we can help. Stephen R. Phillips was here Please be advised what was said may be absolutely wrong, and hereby this disclaimer follows. I reserve the right to be wrong and admit it in front of the entire world. __________________________________ Do you Yahoo!? Make Yahoo! your home page http://www.yahoo.com/r/hs -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist