On 12/12/2013 05:03 PM, Goren Buckwalk wrote:
That brownish color you see is not flux. There would never be any flux on the top of the capacitors. It's caused by the electrolyte leaking out. Probably a close inspection (after you have removed the part) would show some fracture in the aluminum housing, or at least a hole. All the caps should show----- Original Message ----- From: Ralf Mardorf Sent: 12/12/13 04:01 PM To: debian-user@lists.debian.org Subject: Re: Hardware Question about RAM and Capacitors On Thu, 2013-12-12 at 15:45 -0500, Doug wrote:On 12/12/2013 02:11 PM, Goren Buckwalk wrote:A agree regarding to the multi-layer, I only half agree regarding to replacing the capacitors. Could you post a link to a photo? "rusty looking" could be flux, it not implicitly has to be a broken capacitor. We unlikely will be able to spot it by a photo, but you never know. However, if you have to ask, than don't unsolder them on your own ;).Yes, I do have to ask, so I know not to do. Pics I can do. However, the angles a bit rough, me leaning on one leg, system is up and running at the end of rack near the wall, luckily I left the side panels off (hosting site found via search engine, but it seems safe. I made close up and smaller versions, but looking at the pics via the site they must have recompressed them, all are under 1 meg some around .3 meg.): Shaky shot of the worst of the three, other two hidden by CPU: http://s2.postimg.org/lbrkej89l/DSCN1309.jpg (full size) http://s21.postimg.org/nfi2gfet3/DSCN1309_cropped.jpg (cropped in close-up, has red arrow to the worst and yellow pointing to where the other two are hidding) http://s21.postimg.org/pb4url3nb/DSCN1309_cropped_small.jpg (smaller and cropped) - Shot of all three, almost: http://s27.postimg.org/iya7t9gjn/DSCN1307.jpg http://s21.postimg.org/z5vhqwe5z/DSCN1307_cropped.jpg http://s24.postimg.org/qgkgju9z9/DSCN1307_cropped_smaller.jpg http://s8.postimg.org/i33u96j5h/DSCN1307_smaller.jpg - wider but shaky shot: http://s21.postimg.org/qjsqd7vlj/DSCN1311.jpg http://s13.postimg.org/x72ewgux3/DSCN1311_small.jpg
just clean aluminum on top, like the other ones you see in the vicinity.I would be tempted to replace these aluminum electrolytics with tantalum capacitors of the same or slightly larger voltage and capacitance ratings. Under no circumstances use a lower voltage rating than what you are replacing. Much military hardware has been built with tantalum caps, but most consumer equipment
has not, because tantalums are quite a bit more expensive.Whoever is going to do the actual work, remember that electrolytic capacitors--both aluminum and tantalum --are *polarity sensitive*. they *must* be installed with the same polarity as those being replaced. The board itself may be marked--I just looked at a Foxconn mobo, and it has a + sign next to each electrolytic cap. But if not, before removing the caps, mark the board with a + sign where the positive end goes, or with a minus sign where the negative side is. (Aluminum caps are usually marked with a white stripe at the negative polarity. Tantalums, however, are usually marked with a + sign nearest the positive lead.)
Depending on the values you need, you might find them at Radio Shack. They don't have a large selection, and their prices are about 5 times what the actual value is, but for three pieces, that's the simplest.
Otherwise, Digikey will definitely have what you need. --doug