The warranty replacement came from Intel today, it's installed and=20 working Good. The board with bad floppy port, I troubleshooted with the=20 LED's described below, and found a short at the Channel "A" and "B"=20 enable pins at the I/O chip centipede legs which with a strong=20 magnifying glass and sharp dental pick cleaned up, and that is working=20 also. I don't know what the foreign material (it was very small) was,=20 but it must have been at least more than a little conductive, and I=20 don't know where it came from. :) On 3/12/2012 9:51 PM, Carl Denk wrote: > Thanks for the reply. :) > On of the first things I did was check the caps. I have replaced them on > a couple of other boards in the last year. One of my hobbies is: people > give me their older computers, I fix them up, load some basic software > and donate them, where someone puts them to use. Intel is warranting the > dead board, should have the replacement tomorrow. Cost $25 for next day, > but it includes a return shipping label that's worth probably $15. And I > get a box to ship it back in. :) I had to E-mail them a JPG of the > invoice. Other than my call to them, waiting 5 minutes, and 3 calls back > from Intel for details one step at a time, last one to get my credit > card #, was a pleasant experience. > > On the other board, I made up 4 LED's with limiting resistors, plugged > them into unused floppy cable connector both the bad board and a running > one as baseline. Seems that the Motor Enable and Drive Selects for both > A& B are on where only B should be on. Quickly checking, there is no > short to ground or adjacent pins. Seems to be headed to a Super I/O chip > Winbond WPCD374L (around 100 pins) that is nearby on the corner of the > board. Don't think I want to tackle swapping that out, but maybe can > find someone locally if I can find the chip cheap enough. Rehabbed > boards are $35 - $50 inc. shipping. Might even be better than a new > one. And comes with 90 return, so not worth a lot of time. If it's going > to do something, probably will in that time. Going to pursue that more > tomorrow, been a busy day. :) > > On 3/12/2012 8:07 PM, cdb wrote: > =20 >> ::I have 2 defective Intel DP965_LT mother boards with issues: >> >> Sounds like this model or batchis one to steer clear of :) >> >> The first thing I would check is the condition of all the electrolytic >> caps. They may not be bulging, but in heavily used PC's the heat tends t= o >> get to them - if they are solid aluminium, heat stress is unlikely. >> Changing these could well get everything springing back to life. >> >> Note PC boards are at least 6 layer boards and the through hole caps are= a >> pain to desolder and solder back in due to the copper earth layer. >> >> The SMD copper pads showing are probably components not required for tha= t >> model or version of the board - a different version of the same model ma= y >> well have those components fitted, so I wouldn't worry about bare copper >> showing. >> >> I wouldn't use a heat gun (if you are talking about a general purpose ho= t >> air gun) as often they can be too hot and components will desolder and >> board delamintates. An SMD heat gun might be OK for waving in general >> direction of SMD components that have no pins/pads visible in case a voi= d >> or dry joint has become apparent. >> >> It very likely that your motherboards are using lead free solder, so if = you >> see joints that look dull, this may not be a dry joint but just how Pb >> free looks. Soldering Pb free joints will take a little longer to get >> flowing if you are going to try and reflow with standard lead solder. >> >> Colin >> -- >> cdb, colin@btech-online.co.uk on 13/03/2012 >> >> Web presence: www.btech-online.co.uk >> >> Hosted by: www.justhost.com.au >> >> >> This email is to be considered private if addressed to a named individu= al >> or Personnel Department, and public if addressed to a blog, forum or ne= ws >> article. >> >> >> >> >> >> =20 --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .