Thanks for the link. You (and others) were correct. There are 3 caps
right next to this coil and very close to some major power transistors
(probably regulators). All 3 of those caps have bulged tops and there
seems to be a brown stain next to one of them. Until looking at the
pics on this website, I did not know what to look for. It's now
obvious those 3 caps are fried. Oddly enough that motherboard still
boots and runs. In fact I loaded windows and a bunch of hi-res photos
and no problems. I think I am going to see if I can find three 1000uf
caps and replace them. No sense trashing a working motherbd for $5
worth of caps. I wont replace the others, jsut those three. That
coil is charred but it still works. Since the windings dont touch I
dont see where it matters if the enamel is burned off. I got a
soldering iron so what the heck. Maybe I'll turn that into my Windows
98 machine. I still like using 98 when XP ****es me off, which it
does quite often.
Just curious. What exactly do those coils do? Every motherbd has
them, at least 2 of them. They are just a core with about 10
windings. All I can figure is a choke of some sort.
----------------------
On Tue, 15 May 2007 05:44:57 -0500, "w9gb"
wrote:
This may be educational
http://www.badcaps.net/
Personally, I would not have spent a dime for a 500 MHz PC, when Fry's area
selling brand new Pentium 4 with software for $ 299 (last year models being
replaced by new ones).
gb
wrote in message
.. .
A while back I bought a used 500mhz computer on Ebay. (that was my
big mistake). When I got it, it worked well, except for the floppy
drive. I contacted the seller immediately and he sent me another
floppy drive to replace the bad one. I replaced the drive and turned
it on. It worked fine but since I wanted to add another harddrive (as
soon as I got one), I left the cover off the case. That turned out to
be a good thing, because I was sitting at my desk on the web when I
noticed a hot burnt odor. Then I saw smoke. I looked at the computer
and saw smoke coming off the motherboard. There are these donut
looking things on the board. They look like a white lifesaver candy
wound with 20 or 30 loops of a fairly thick enamelled wire (actually
not all that thick, probably a 20 gauge). Oddly enough, the computer
continued to work the whole time, and I know that because I saved
whatever I was typing before I shut off the power. I found all the
enamel burned off the wire on that coil and it was black. I was glad
the cover was off the case so I could see what was happening.
I carefully looked for anything that might create a short and found
nothing. I got my fire estinguisher (just in case), and turned the
computer back on. It booted up, and worked fine. I turned it on and
off several more times, and it still worked, and I never saw more
smoke. The seller would not replace it because it was 2 ot 3 weeks
later by then.
What could have caused this? What are those coild called and what is
their purpose. It seems there are 2 or 3 of them on all motherboards.
Needless to say, I do not use this computer. I dont trust it. I just
took out all the drives, ram, and cards and put them on another
motherboard. I know I can use that case again, but question the power
supply. I definately will not use the motherboard again, and worry
about the CPU.
Anyone have any idea what caused this? I'm just curious more than
anything else. I figure the MB is best going into the trash, and I
have a faster CPU now too.
Thanks
Plumber