Most likely, there were and are no shorts on your boards. But there are lots of capacitors. An ohmmeter measures the current. Depending on the charge of those capacitors at the time you measure it, the current may be small, big, positive, or negative. After powering off the board, they probabbly had some charge they didn't have before, and so the current and the reading differed. If you left the ohmmeter connected overnight, it might approach the same reading regardless of whether the board was ever powered or not. (It might take longer than overnight.) Try measuring the resistance of just an electrolytic capacitor. Reverse the leads a few times and see what happens. Even without capacitors, 0.5 ohms isn't much of a short, if you are measuring at the power planes. Your 14A regulator wouldn't blink. Expect a real short to measure a lot less resistance. Regards, Andy ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu