Hi, John Don't know if you are the same John Anselmo I used to work with at ADC Telecommunications? Anyway, this varistor typically has a voltage present which changes as the current increases/decreases dependant on temperature. If any flux from the connector soldering operation, or for that matter any moisture is present under the varistor, it greatly affects the performance of that particular component. You may wish to try and direct a de-ionized water spray directly at an angle to get as much volume under the varistor as possible, followed by a 15 minute bake at 105 deg. C to get the board clean and dry. Try this on just one or two failed units first, and then re-test without reworking. If this fixes the issue, your suspicions will be confirmed. The other option is to mask off the area prior to the connector soldering to prevent the flux from getting under there. It may be flux remaining from the solder paste as well. I would start by ensuring the board under the part is clean and dry and re-testing. If that does not fix the issue, then you may have a problem with the test heating up the part and getting a false fail. But based on the fact that you can hand solder the part or re-solder the part and then it passes test, my guess is you are removing the moisture under the part when you do that, and then that portion of the circuit operates as it should during subsequent testing, resulting in the assembly passing test. R. Dean Stadem -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of John Anselmo Sent: Tuesday, July 29, 2008 4:09 PM To: [log in to unmask] Subject: [TN] Ceramic Varistor Test Failures Dear All, We have been seeing an increase in test failures of the ceramic varistor (AVX P/N VC060314A300) when these components are near a connector that we hand solder. I suspect it is contamination from the flux used for hand solder. We fix the test failure by resoldering the varistor, and all is well at retest. We do a water wash after hand solder, but still see a 20% to 40% test failure rate. Has anyone experienced this before? Waht was done to fix the problem? Thanks in advance for the help. John Anselmo Manufacturing Engineer S&K Electronics, Inc. --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------