Re: [PEDA] OT - Complex boards and time to Layout? - Shorted Planes
[EMAIL PROTECTED] wrote: Run a couple of amps (from a current limited power supply) through the short and use a 5 1/2 digit voltmeter on the millivolt range and you can get the short circuit location fairly easily. Yes, that's the procedure. But, with perhaps 500 holes tied to the ground plane, covering the whole board, the voltage drop across the planes can be REAL small. I ran 6.5 A between the power plane and ground, and was able to apply about 15-20 mV between the planes. The actual location of the short was found at a through hole with about 2 mV difference than the neighbors. But, there was probably 5 mV of voltage drop across the planes. So, it had to be compared to local pads that weren't shorted to spot the bad one. Then, I had to burrow into the board, through 2 layers, to dig out the short right next to a grounded pad. Jon * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout? - Shorted Planes
Run a couple of amps (from a current limited power supply) through the short and use a 5 1/2 digit voltmeter on the millivolt range and you can get the short circuit location fairly easily. Jon Elson [EMAIL PROTECTED] on 27/09/2002 07:43:21 AM Please respond to Protel EDA Forum [EMAIL PROTECTED] To: Protel EDA Forum [EMAIL PROTECTED] cc:(bcc: Clive Broome/sdc) Subject: Re: [PEDA] OT - Complex boards and time to Layout? Danny Bishop wrote: funnily enough it never happened to me, I have never found a fault on my boards, and hence don't concern myself too much with the tests on basic double sided. I've hardly ever had a problem on 2-sided, and they are easy to spot visually and fix in a moment. But, major trouble deep inside a 6-layer board will drive you nuts! Locating the exact point where two split planes or two power planes are shorted is a real bear! Jon * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout? - Shorted Planes
There is also an inexpensive instrument ( about $180US ) called Leak Seeker from Electronic Design Specialists ( www.eds-inc.com ) that does a very respectable job of finding the location of internal board shorts. It takes a little practice to get the most out of it, but it does work. Polar Instruments ( www.polarinstruments.com ) also makes a similar instrument called ToneOhm, but it is on the 'pricey' side. At 10:45 AM 9/27/02 +1000, you wrote: Run a couple of amps (from a current limited power supply) through the short and use a 5 1/2 digit voltmeter on the millivolt range and you can get the short circuit location fairly easily. Jon Elson [EMAIL PROTECTED] on 27/09/2002 07:43:21 AM Please respond to Protel EDA Forum [EMAIL PROTECTED] To: Protel EDA Forum [EMAIL PROTECTED] cc:(bcc: Clive Broome/sdc) Subject: Re: [PEDA] OT - Complex boards and time to Layout? Danny Bishop wrote: funnily enough it never happened to me, I have never found a fault on my boards, and hence don't concern myself too much with the tests on basic double sided. I've hardly ever had a problem on 2-sided, and they are easy to spot visually and fix in a moment. But, major trouble deep inside a 6-layer board will drive you nuts! Locating the exact point where two split planes or two power planes are shorted is a real bear! Jon snip * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
