June 22, 200818 yr I'm posting this in the hardware section rather than the motherboards section because i'm not sure the problem lies with the motherboard. I've been happily running unRAID for a while now, but for the last couple of weeks i've had an interesting powerup/powerdown problem. When i powered up the machine (either by the front switch, or wake on lan) the hard drives wouldn't spin up, and the screen would remain blank.. No post, nothing. I'd then switch the machine off by the power button, and after about three seconds it'd turn back on, run for a couple of seconds, then turn off. Then pushing the power button again would yield life for a few seconds, then it'd power off and power back on - booting up normally. The problem wasn't just booting up either, 4 out of 5 times i shut down the machine (via the web interface) it'd power up again 10 seconds or so after power down. I spent a while trying to diagnose it, deactivating Wake On Lan etc. With no luck. I've tried replacing the PSU, i've tried booting it without the hard drives connected, i've tried using a new case switch (incase it was jammed), i've updated to the latest bios and i've tried without the unRAID USB stick connected. No luck. This seems to be pointing to a motherboard problem, which really bothers me because i put a lot of effort into locating/purchasing the recommended unRAID motherboard, and it was too expensive to just throw away and replace without thought. Any ideas?
June 23, 200818 yr I saw this earlier and was hoping Joe L. or one of the other long-term members would have a magic bullet for you. I see no one has responded so will try to help ... I have that MB. It has this weird power on cycle. When you plug it in, the power will come on for a second or two and then go off immediately. But when you turn it on from the case switch, all seems normal. I think when you do a reboot it actually powers itself all the way down and then spontaneously turns itself back on. Never seen another MB like it. But a shutdown is a shutdown - it stays off. I do not use any "wake on" features. Your symptoms sound like some of this has gotten out of whack. One thing I'd try is to reset the BIOS settings (should be a reset option). Then go through all your settings carefully. Do not turn on any of the wake on functions, and try to turn off most everything (audio, etc.) (When you upgrade BIOS, you should ALWAYS reset the settings to default within the BIOS - normally there is a button that says "load defaults" - and then remake any changes.) You've tried most of the other things I'd recommend. MB problems are hard to diagnose, as when they go bad almost anything can happen. The PSU would be high on my list of candidates, but you said you tried another. Memory is another common culprit, but this does not sound like a typical memory type issue. Are you having any problems once the machine is booted up? I leave my box on 24x7 and let unRAID spin down the drives to save power. Only time I reboot it is to upgrade the OS or add a drive. If I had a finicky booting MB, it wouldn't be so aweful on my unRAID box. Now if it is flaking out in other ways, I'd have to toss it and maybe try the ABIT board. Good luck!
June 23, 200818 yr I saw this earlier and was hoping Joe L. or one of the other long-term members would have a magic bullet for you. I see no one has responded so will try to help ... I don't have any experience with that motherboard. It is not a unit/Linux/unRAID issue. I too would suspect the power supply... but, you have already tried another. Sorry, but I don't have a clue...what to look for...perhaps your memory needs higher voltage than you are supplying?? 2.1 volts vs. 1.8??? One website had a thread: I think I have a workaround for you. I have changed the Memory clock Freq to533MHz, DDR Voltage: 1.95v and set the switch to remapping. Now it works fine. The problem I think is that the ASUS P5B-VM doesn`t support DDR voltages more the 1.95V!! 2.1V is needed for 800Mhz! I hope ASUS will fix this ASAP. Other ideas here: http://www.silentpcreview.com/forums/viewtopic.php?t=35573 Apparently, you are not alone with these symptoms. And more: http://forums.hexus.net/yoyotech-care-hexus/139280-problem-newly-built-pc.html#post1431660 Joe L.
June 23, 200818 yr Author Hey guys, Thanks for the in-depth responses! I had some progress last night, success and a little mystery. My unRAID box is housed in an Antec Sonata case (i think it's the first revision of the Sonata), and i use the Antec power supply that comes with it (i believe it's a 380 or 340w). When the problem first started to get severe, i had two ideas - either the power management settings (in the BIOS, ACPI etc) or the PSU. I tried every setting in the bios, reset it and even upgraded the bios to no avail. So i tried another power supply, out of my second Antec Sonata. The problem kept occurring. I got a bit paranoid yesterday and borrowed a power supply from a friend - a new 400w one. I fitted it and the problem was resolved! I was a little worried because switching on the PSU starts up the machine for a couple of seconds, which i thought to be the beginnings of a relapse, but bjp999 has confirmed that is the norm for this board. So the mystery.. My Antec supply worked fine in this machine for four months, with no hardware changes. Then once the problem arises i try an exact copy of the PSU and that doesn't resolve the issue. But a different newer supply does. Why could this be? Have the Antec supplies degraded in the same way? Perhaps not putting out the exact voltage that the motherboard needs? I read something about newer PSUs having "two 12v rails".. Could that be something to do with it? Thanks guys
June 23, 200818 yr Glad that you have made some progress! It sounds like maybe the Antec PSU is not supplying enough of some kind of power that the MB uses. Watts don't tell the whole story - the watts are distributed to different voltages (normally documented on the side of the PSU). You don't post much about your system 340-380 watts may also just not cut it with the number of drives, memory, etc you are running. You may never get a good explanation as to why one model PSU works and another doesn't. I'd likely just get a new PSU that gets good reviews. Depending on the number of drives you plan to use, you can size the PSU. 650W is a good size if you plan to max out the array. I wouldn't go with anything less than 450W.
June 23, 200818 yr Author Well see that's the thing, the PSU did work perfectly for four months. Then suddenly stopped! I'm fairly sure my spec isn't causing the problem (not enough power etc) because i tried without any hard drives, and the problem continued. But for completeness: Motherboard: Asus P5B-VM DO Processor: Intel Celeron 440 2.00GHz Socket 775 FSB800 RAM: Kingston 2x512MB DDR2 800MHz/PC2-6400 Hard Drives: 3x Western Digital WD1000 1TB RE2 Green Power drives According to a calculator i tried online, i should only be drawing around 200w, so i'm thinking about going for a 500w Seasonic S12II-500 PSU, which gets great reviews.
June 24, 200818 yr A few things may have happened: * Higher heat in the summer means lower wattage output of the PSU and higher wattage requirements if you have temp-adjusted fans (OK, maybe only a watt or two for the latter, but ya' never know!) * You may have a slight short (single strand of wire) - try blowing out everything with compressed air and also try unplugging/replugging all the cables * OK, OK, I'm with bjp999 ... gremlins! Bill
June 24, 200818 yr Heat is a silent killer. If your power supply was working near the top end for a long period of time and was hot, this could cause capacitors to expand and/or dry up. Heat in the case can also cause capacitors to dry up, expand or become weak. Examine all with a strong flashlight just to be sure.
June 24, 200818 yr Author I discovered that the bios for the P5B-VM DO reports, among other things, the voltage of the 12v rail. For the troublesome power supply it reports a figure along the lines of 11.5v, whereas the working PSU reports 12.5v. Could that 11.5v be causing the problem?
June 24, 200818 yr It is out of spec. Being on the high side isn't all that great either. If it's rock solid then you should be OK, It's deadly to have rails that fluctuate.
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