You may be having a problem with ground loops. Try connecting everything to a single grounding point. Any shielded cables should have the shield grounded at one end only. I know it sounds screwy but it makes a difference.
Joe At 08:09 AM 8/20/03 -0800, you wrote: >Hello members, > >I've encountered a strange problem which I would like to share with you. > >I'm working on a device with a build-in modem. It uses a AC/DC (220V to 5V) >converter as powersupply. Somehow the modem does not work correctly and does >not want to pick up the line. Connection with the processor seems to be OK, >both timing and message content. > >The following strange thing happens: >Only connecting the ground of a scope probe to the ground of the PCB makes >the modem work. I suspect it to be a grounding problem, but don't have any >clue how to solve this. The PCB has a full ground plane, so this must be >good. > >Any ideas? > >Kind regards, > >Elbert. >-- >Author: Elbert Smit > INET: [EMAIL PROTECTED] > >Fat City Network Services -- 858-538-5051 http://www.fatcity.com >San Diego, California -- Mailing list and web hosting services >--------------------------------------------------------------------- >To REMOVE yourself from this mailing list, send an E-Mail message >to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in >the message BODY, include a line containing: UNSUB CHIPDIR-L >(or the name of mailing list you want to be removed from). You may >also send the HELP command for other information (like subscribing). > -- Author: Joe INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB CHIPDIR-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
