Hello teachers, we have the following problem in some class 3 units: we have detected a white stuff inside the contacts of female connectors. It could be the main cause of the failures found during testing. Our thought is this substance could be due to a reaction between the rosin flux used when soldered the connectors whit the cleaning solvent (IPA) Two questions: 1) Could you recommend a solvent to remove these residues. We have tried with 141-b, but it could damage some parts of the unit. 2) We would like to send a contaminated connector to a lab for analisys. Could you recommend a technique to determine these substances? Thank you for your help. Juan T. Marugán Indra Sistemas SA España --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 -----------------------------------------------------