Subj : USB lock up - poo! To : Ky Moffet From : Barry Martin Date : Thu Oct 29 2020 07:53:00 Hi Ky! > 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> Unfortunately, it missed the haystack! Missed the needle that way! > 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. KM> Ah. If I ever get around to attempting such a solder job, I'll KM> have to consider larger caps (plenty of boards and PSUs to KM> cannibalize) cuz now I'm thinkin' that some of the iffy caps of KM> the plague era might not have gone POOF if they weren't being KM> driven to max capacity. Quite possible. For 'max capacity' I'm thinking voltage, so increase: go from (say) 12v to 16v. > 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> Can you print in the snow too?! Back to capacitors, I'd stay with the same value or slightly more (ex.: original 470 mfd, go 'up' to 510 rather than 'down' to 400). There are quite a variety of capacitors (^*), but if you're cannibalizing from another motherboard I'm thinking the type will be correct. (^*) Sloppy analogy: think 'capacitors = cars'. They all do the same thing but differ in versions. Electrolytic, tantilum...; pick-up, sedan....) Getting rather wet around here with all that whizzing! And the wind's picking up -- euwwwww!! > 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 KM> When it's not working at all, I doubt it matters if you fix it so KM> it runs a bit slower than design specs! Now that you mention it, it does seem to significantly improve performance!! > 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> Who knows. But here are some Handy Charts showing what connects KM> to what: KM> https://en.wikipedia.org/wiki/Southbridge_%28computing%29 Thanks! I had seem something similar but this tends to explain it at a simpler level, especially the last diagram. > 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> Given the above chart, I wonder if a drive attached to PCI-E is KM> out of that loop. Per the last diagram appears yes, though the article indicates Southbridge may support PCIe. Just might be worthwhile to check. (I wonder if a PCIe USB daughtercard would solve?!) > 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! KM> KM> Where do you live? KM> I dunno, my house moved. Commonly said of beachfront properties. ¯ BarryMartin3@ ® ¯ @MyMetronet.NET ® .... I had to sell my vacuum because it was collecting dust. --- 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) .