Subj : USB lock up - poo! To : Ky Moffet From : Barry Martin Date : Tue Oct 27 2020 07:20:00 Hi Ky! > KM> Yeah... I wouldn't expect the logfile to be written. > OK, so seems a Southbridge problem is being confirmed. KM> Sadly. It is sort of a good news/bad news item. Good news is I don't have to spend lot of time trying to figure out where the problem is and possibly what part to replace. Bad news is it is sort of an expensive item, or pair of items as I'll probably replace with an Intel motherboard so I can go with an Intel CPU. > KM> Assuming it's the caps, but yeah, and the real fault, at least > KM> per what I found re mine, is a design flaw in the Southbridge > KM> circuit that cooks the capacitors. So replacing 'em would work > KM> for a while, but eventually they'd fail again. > And probably can't replace with larger values as wouldn't physiclly fit. > Using ribbon cable to run to a 'capacitor card' would take care of the > size problem but probably cause a timing issue. KM> Ya know, that's an interesting thought... so you're saying you KM> can use a larger capacitor in the same spot? Hmmm.... Voltage being the larger value I'm thinking about, yes. Usually a larger voltage capacity also means a larger physical structure which may not fit in the allocated space. There is also the capacitance (the 'Farad' part, smaller being microFarad, or mfd, æfd). In DC (direct current) filtering a larger value (up to a point) will reduce ripple (AC/line noise). again with a larger physical size. I might go up a notch or two on the capacitance -- there are other factors like charge and discharge rates, I don't have the background being 'just' a hobbyist. I'd feel more comfortable playing with the values in a power supply than in a computer curcuit. KM> No need for a card, if you're replacing caps that don't want to KM> fit at the original height, just put 'em up on legs (longer wires KM> soldered into the holes). I've actually seen that done. Looks KM> like aliens marching across the board. :) In fact the loose caps KM> I've seen have long enough wires to do this. Use a bit of plastic KM> straw as an insulator, if bare wires are a problem. Agree: have seen that done professionally as well as done it myself. That little trick will get one in trouble with higher speed circuits -- thinking specifically RF where even the component sitting a little above the board versus sitting flush will alter overall values. ...I'm not quite sure what the capacitors around the Southbridge circuit actually do: filtering? timing? blocking? I'm thinking DC filter because of leakage issues so the extra lead length probably wouldn't make any difference for that short a distance. And can probably halve the feeder wires plus one as is a common ground. > KM> Well, mine got repurposed to what it CAN do... was sad to retire > KM> it from everyday use but I kinda needed the whole thing to work! > Yes: "perfectly good except for". LIS I can't think of a non-critical > usage here which still takes advantage of the multi-core/higher speed > CPU. Maybe NAS? I'm a bit concerned about the Southbridge-controlled > read/write to hard drives. KM> Yeah, does seem kinda iffy for that. But as repurposed mine KM> rarely writes a file other than whatever internal housekeeping KM> linux does, and if it gets bogified, no one cares. No longer a KM> critical system, just a handy one. OK, yes. I was initially thinking only the USB circuit being munged but then remembered it is part of the Southbridge circuit, which controls a whole heck of a lot of other stuff including the hard drives. Back to not being a good choice for a critical system. Maybe testing/isolation, though what little testing I do I tend to use the Virtual Linux Machine. > KM> Hopefully the New! Improved!! PCs will do the job better for a > KM> long time... > Hopefully! ...Did see a MSI motherboard being offered the other day on > a Shell Shocker special -- I did perk up but right now too many other > projects going on to check out its details, especially which (Intel) CPU > to get. Quite sure more will be available . KM> Didn't notice that one, but haven't been paying attention as not KM> really in the market at present. In fact I haven't finished KM> moving from Cash to Silver II. Grrr... I hate moving house.... Sometimes it's bad enough when isn't moving! ¯ BarryMartin3@ ® ¯ @MyMetronet.NET ® .... Microfiche and integrated circuits: fiche and chips? --- MultiMail/Win32 v0.47 þ wcECHO 4.2 ÷ ILink: The Safe BBS þ Bettendorf, IA --- QScan/PCB v1.20a / 01-0462 * Origin: ILink: CFBBS | cfbbs.no-ip.com | 856-933-7096 (454:1/1) .