On 7 June 2016 at 20:09, Aleksandar Kuktin <[email protected]> wrote:
> -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > >On Tue, 7 Jun 2016 19:36:43 +0100 > >Ken Moffat <[email protected]> wrote: > > > > On 7 June 2016 at 18:18, Aleksandar Kuktin <[email protected]> wrote: > > > I'm not familiar with the sound a dead psu makes. I had one a few > > years ago, all I remember is the burnt smell. The sound is > > high-pitched, probably in the high hundreds of Hz, or maybe 1 KHz. > > But before I sent this reply I googled for the sound of a dead PSU - > > one forum post where a new PSU solved the problem does seem to match > > what I'm hearing. > > I would have been "happier" with, say, 50 kHz because switching power > supplies (the kind that gets put into PSUs) usually operate internally > at about that frequency. > I don't think I would hear even 15 KHz. [...] > > >> I'm not clear about the actual symptoms you are having. I'll post my > >> understanding, you correct my mistakes. > > > For the test machine: as soon as I turn the switch on the PSU to 'on' > > the sound starts. If I then press the power switch on the case the > > motherboard and CPU fans both start, but I seem to not have any video > > output (that might be luser error - the KVM switch is dieing, only one > > position works reliably, maybe I misconnected after failing to boot > > the test machine to try to do a clean shutdown andlater swapping it > > back). > > Does it beep? A properly operating motherboard will beep twice. In this > case, the most important beep is the first one. That's the motherboard > firmware saying "I'm alive". Fans are simple devices and will operate > even if the PSU outputs "wrong electricity", say a train of 100Hz > pulses instead of a steady voltage. > > No beep. But I don't think it has any speaker connected. > > [snip] > > > > Getting space to open them is a pain, but yes I have other machines > > (using one of them at the moment). > > You'll probably need to open the machines. > > The traditional way of doing this is to have a known good computer and > then swap in parts from a broken computer, waiting to see when it will > fail. In theory, I'd first concentrate on the disks and make sure they > are alive. If the disks failed (got fried), then you will at least > discover that early. But in practice, it's probably good enough to > replace the PSU with a known good one and see if the machine boots. > Make sure the KVM magic is working well. :) If it does not boot, I'd do > the whole transplant-bit-by-bit ritual. Beware hasty conclusions. > > Yes, I've done this in the past. That test machine is the one I would have used to test a new or doubtful disk (light case, easy to access in its current location) - using one of the others will take a bit of time. > > The server would have been running and I won't be surprised by a > > failed PSU. But the test machine was using minimal power (nominally > > powered off, probably 5 Watts maximum) and it is perhaps a year old, > > maybe two, but unlikey to be more than that. > > Hmm.. bizarre. Yet, everything is possible. Note that the fact the PSU > was switched off may not be of any significance. There's no way to know > without knowing more about its internals. > Thanks. I'll see about looking at the SSD from the test machine, then probably get a PSU or two. For the moment I'm not touching the server, I seem to have developed an ability to break things recently. ĸen
-- http://lists.linuxfromscratch.org/listinfo/lfs-chat FAQ: http://www.linuxfromscratch.org/blfs/faq.html Unsubscribe: See the above information page
