At 2003-01-17 02:23 -0800, contescu mihai wrote: >Thank's, for help, >I have 2 videotelephon AT&T 2500, one work and else >display: > >"System failure, >for any problem see Owner's manual" > >Battery, cable and voltage is OK. >Display and camera is OK. >What can I do? >Thank's Mihai
If the IC's are in sockets you should slightly lift them up about 1 mm at one end with a screwdriver (or preferably 0.5 mm at both ends with a genuine IC-puller) and then push them back in again. When you use a screwdriver, first push on the end that was lifted and then the other side usually comes up. Then you push both ends at once. The reason for this seemingly strange procedure is that the pins often get corroded after say 5 years, especially in a moist or chemically 'challenged' environment. You should do the same with all connectors. (You can also pull them completely loose.) By slightly moving the IC's you'll scrape of the corrosion. It's not wise to completely remove and reinstall the IC's because you risk bending a pin. This risk normally isn't present with connectors. Most connectors and sockets are designed so that when inserting the connector (or IC) the corrosion is being scraped off. You can also just re-solder all the points on the downside of the printed circuit board. A more solid solution is removing the sockets altogether and solder the IC's into the board permanently. If you have little experience with repairing electronics it is probably a good idea to ask a professional for help. Most repair shops know of these general tricks and can often repair stuff without having to have manuals etc. Also bring the working device so they can compare them and exchange parts to locate the problem. It's very unlikely that normal IC's stop working correctly, but EPROM's can be an exception, for example because their UV-window isn't properly covered or they were programmed incorrectly and have lost their content (but this isn't very likely). All parts that move are candidates for breaking. Also all electronic parts that are connected to the outside world or that handle large currents or voltages. You can find links to more repair tips on my site at: http://www.chipdir.info/abc/r.htm#repair Greetings, Jaap -- Chip Directory -- http://www.chipdir.biz/ -- http://www.chipdir.info/ -- http://www.chipdir.net/ -- http://www.chipdir.nl/ -- http://www.chipdir.org/ -- And about 30 other mirror sites world-wide. -- -- To subscribe to a free 'chip issues, questions and answers' -- mailing list, send a message to [EMAIL PROTECTED] with -- in the body 'subscribe chipdir-L'. About 500 experts are -- willing to think with you about electronics problems etc. -- Author: Jaap van Ganswijk 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).
