.... or access to one? I have one here and all of the wires to the front switches etc. have been pulled from the board. The only 'manual' that I can find doesn't cover things like that and I'm slowly losing what's left of my sanity trying to troubleshoot a mobo that I can't even connect up properly! A pic of that area around the southbridge would be a wonderful thing - failing a 'proper' srvice manual. TYVMIA. -- /Shaun. "Humans will have advanced a long, long, way when religious belief has a cozy little classification in the DSM." David Melville (in r.a.s.f1)
Please disregard, problem sorted. -- /Shaun. "Humans will have advanced a long, long, way when religious belief has a cozy little classification in the DSM." David Melville (in r.a.s.f1)
I have one of these that works perfectly, one that works somewhat and one that doesn't do anything but pulse the fan (and LED) when power is applied. I saw a bunch for sale on TM a while back listed as having bad capacitors. The guy was selling the 'bad' PCs (sans RAM, CPU and HDD) in lots of 20 for very little. The behaviour of the one I have that works *somewhat* makes me think that it IS caps that's the problem with it and also with the bad one. The problem is that the nine caps around the CPU socket that are obviously the VRM caps are of the polymer type (4V 560uF) - the caps that were supposed to cure the 'bad caps' issue. There are also five big 'wet' electrolytics (16V 1500uF) in the general area but they all /look/ good. In the past, IME, it's always been the 6.3V VRM caps that have given trouble. They're the ones that do the most work. 6.3V was the lowest common voltage for 'wets' whereas polymers use different voltages. They're there for 'smoothing' the vcore, to give the CPU a constant voltage - which is usually well under 2V. They leave a margin for headroom so 4V makes sense. So... Polymer caps don't have the stamped-in venting that wets do as they don't produce pressure when they fail. Therefore they don't visibly fail - a real PITA for folks like me who have been known to replace failed caps on a mobo and then have it run for years. If you can't see the bad ones then how do you know which ones they are? Well, the real issue is has anyone here seen an Acer Veriton 3900Pro with failed caps? I need to know if it *is* the polymer VRM caps that fail. I have an Intel dual-socket Xeon server board here that was never used that I was intending to sell on TM. The trouble was that it only had one (single-core) Xeon fitted and consequently nobody wanted to pay enough for it... The good news is that it has 40 (yes, *40*) Sanyo OS-CON polymer caps (unused remember) of the same value (4V 560uF) as the 9 on the Acer board. http://www.capacitorlab.com/capacitor-types-polymer/ They are a little taller than the (unknown brand) caps on the Acer but that's not a problem. I can swap them over - in fact that's why I still have the server board - all those luverly capacitors. However if possible I'd like to get confirmation that it is the polymer caps that fail on the Acers. I'd hate to do the swap only to find that it's the bit 16V wets that fail (without showing). To me it's worth getting these boards going if possible. They cost me $30 each... but they're from 2006/7 and can take 45nm Core2Duo CPus of 800 or 1066MHz FSB. That makes them still quite useful. So if anyone has experience of Acer Veriton 3900Pros (or knows someone who does and can make a quick call to confirm...) and can let me know if I'm on the right track before I get the soldering iron out I'd be very grateful. TIA, -- /Shaun. "Humans will have advanced a long, long, way when religious belief has a cozy little classification in the DSM." David Melville (in r.a.s.f1)
I have had 3 of the previous acers (p4 based) have dickky caps in the power supply. Mobo was fine. THankfully they were standard micro atx boards so they were rehomed into the cheapest nastiest case available at the time. One of them is still working doing my torrenting these days.
Thanks Richard. Yeah, I know that they can have capacitor issues in the PSUs too but I have several here and that's not what's causing me grief right now. I can't find any info on who makes the polymer caps in the VRM but everything that I read says that polymer caps in general are many times more reliable than wet electros. *However* there are five 16V 1500uF (wet electro) caps on each mobo that aren't part of the VRM but, when Googling or checking places like badcaps.org, they come up as about the worst caps ever made and are known to fail without showing any visible sign that they have done so. Unfortunately I'm not really in the position to go throwing good money after bad (as my old Dad would say) without some sort of pointer.... It's 'only' a couple bucks a cap to buy (plus gas to get to Jaycar...) but it'd be nice to know in advance if that's likely to be the answer - rather than the VRM polymer caps. Cheers, -- /Shaun. "Humans will have advanced a long, long, way when religious belief has a cozy little classification in the DSM." David Melville (in r.a.s.f1)
