From owner-freebsd-questions@FreeBSD.ORG Sun Jan 15 13:29:52 2012 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 522EA106566C for ; Sun, 15 Jan 2012 13:29:52 +0000 (UTC) (envelope-from dave@g8kbv.demon.co.uk) Received: from lon1-msapost-1.mail.demon.net (lon1-msapost-1.mail.demon.net [195.173.77.180]) by mx1.freebsd.org (Postfix) with ESMTP id 160308FC12 for ; Sun, 15 Jan 2012 13:29:51 +0000 (UTC) Received: from dyn-62-56-56-229.dslaccess.co.uk ([62.56.56.229] helo=[192.168.42.15]) by lon1-post-1.mail.demon.net with esmtpsa (AUTH g8kbv) (TLSv1:DES-CBC3-SHA:168) (Exim 4.69) id 1RmQ9e-000521-XI for freebsd-questions@freebsd.org; Sun, 15 Jan 2012 13:29:50 +0000 From: "Dave" To: FreeBSD Mailing List Date: Sun, 15 Jan 2012 13:29:45 -0000 MIME-Version: 1.0 Message-ID: <4F12D4C9.29852.83B51E@dave.g8kbv.demon.co.uk> Priority: normal In-reply-to: References: X-mailer: Pegasus Mail for Windows (4.62) Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7BIT Content-description: Mail message body Subject: Re: Probable Hardware Failure X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 15 Jan 2012 13:29:52 -0000 On 14 Jan 2012 at 16:12, Doug Hardie wrote: > I have a pretty old desktop that has been around quite awhile. It has > started periodic crashes. No log messages. However, the core status > files all show "double fault". I am confident this is a hardware > issue, but is there any easy way to determine if its power or memory > related? Those are the primary candidates although memory is also > possible. We really need to replace the entire unit, but that might > be a bit more salable if I can present convincing evidence of the > cause of the problem. > Doug. First check the Power Supply voltages are correct, and not too noisy. You'll need a good DMM, and 'scope for that. Then, Visually examine the motherboard. Are any of the round can electrolytic cap's "Bulging" at the top, or showing some brown or green gunk leaking out from where they sit on the board. Likewise, it's often worth checking the low voltage caps in the PSU too. CAUTION! Lots of volts exist in places inside them, take care, leave it a few mins after unplugging before taking it apart. If so, it's not uncommon, you'll need to re-cap the Mobo, and or the PSU. Chances are, it's just one particular make/type that has failed, so if the others look OK, just change the failed ones. Get the same value and voltage, but if you can from a reputable manufaturer, Panasonic or some such. NOTE! It's not uncommon either, for some parts to be installed at manufature the wrong way round. It's amazing they last as long as they do before letting go. Also, at least one Mobo maker had the wrong polarity markings on the board. In those cases, you'll need to "buzz out" the associated power rail, comparing the polarity of the suspect part, with it's copanions on the same power rail. For some common Mobo's, if you google the model number, you'll find websites selling complete re-cap kits, or offering an exchange service. This is A LOT more common, than failing RAM, but can present itself in many and varied ways, from corrupted display's, to systems that wont boot. Laptops are not immune to this either. Also, Hard Drives can "go funny" with age, not failing as such, but the surface getting corrupted so that the drives own logic cant always unscramble the mess to the OS's satisfaction. Then, there is the situation (I had one recently) where a failing PSU, caused Hard Drive data corruption. Mr Gibson's product "Spinrite" is the tool to use to fix that (and it did!) Not free, but more than worth the weight of a CD, Floppy or USB stick in Gold! But you'll need to make sure the Mobo and everything else is OK. It also works on Floppy drives, if you "Just HAVE" to recover that data. If you have a fleet of machines, you should have your own copy. No affiliation, just a more than happy long term owner/user of that tool. (www.grc.com) I've resurected more than one "Sick" PC by following some or all of the above, there again, I can wield a soldering iron with the best of them, and have the test gear to hand to fault find these things, and a source of parts. But it saves a shed load of money if you can afford the time to do it... Hope something helps. Best Regards. Dave B.