Re: Computer died
Additioal question how canyou test if power supply is dead with a multimeter? I'm not a hardware guy On Apr 3, 2011 7:53 AM, Jerry Feldman g...@gapps.blu.org wrote: Yesterday I went to add an old IDE drive to the IDE port on my system (Penguin 3000) and I've not been able to power it on. I don't have a working multimeter, but it looks like it is probably power supply. When I press the per button nothing happens, but occasionally the per light comes on for a second. The old drive has been removed. In any case I can use the Android to email :-) ___ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss
Re: Computer died
On 04/03/2011 09:26 AM, Jerry Feldman wrote: Additioal question how canyou test if power supply is dead with a multimeter? I'm not a hardware guy Whoa! Switching power supplies have to be tested with a load on them: they need the load to deliver proper voltages, and can be damaged if started without one. The problem is that you can't be sure if the motherboard is in trouble, the power supply, etc., without sectionalizing the components, and you'll need a test jig to do that. Something as simple as a three automobile brake lights will usually do, but you'll need a 6-volt lamp (good luck finding one!) for the +5 lead. You can build a test jig with lamps or resistors, and I always intended to but never did: it's easier to swap in a new supply. I recommend you check the existing supply for blown fuses (if there are any: some supply manufacturers don't bother) and then try a new supply. HTH. Bill -- This line of life is quick and keen The time arrives - the knife is clean I am older now and I have seen Great flames of life expire - Dave Mallett ___ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss
Re: Computer died
On 04/03/2011 10:52 AM, Bill Horne wrote: On 04/03/2011 09:26 AM, Jerry Feldman wrote: Additioal question how canyou test if power supply is dead with a multimeter? I'm not a hardware guy Whoa! Switching power supplies have to be tested with a load on them: they need the load to deliver proper voltages, and can be damaged if started without one. The problem is that you can't be sure if the motherboard is in trouble, the power supply, etc., without sectionalizing the components, and you'll need a test jig to do that. Something as simple as a three automobile brake lights will usually do, but you'll need a 6-volt lamp (good luck finding one!) for the +5 lead. You can build a test jig with lamps or resistors, and I always intended to but never did: it's easier to swap in a new supply. I should have one I can lend you if you want to try that. ___ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss
Re: Computer died
I read online that 1. Disconnect the 24 pin connector from the MB 2. Short out pins 15 (gnd) anbd 16(power on). 3. Test pins with voltages. In any case with the power supply connected to the MB I was getting nothing, not even a fan. The article I read was specific to the 24-pin ATX 12V power supplies. another thing I did was to change the power cable. In any case, the multimeter read 0 when connected to ground and several other oins. On Sun, Apr 3, 2011 at 10:52 AM, Bill Horne b...@horne.net wrote: On 04/03/2011 09:26 AM, Jerry Feldman wrote: Additioal question how canyou test if power supply is dead with a multimeter? I'm not a hardware guy Whoa! Switching power supplies have to be tested with a load on them: they need the load to deliver proper voltages, and can be damaged if started without one. The problem is that you can't be sure if the motherboard is in trouble, the power supply, etc., without sectionalizing the components, and you'll need a test jig to do that. Something as simple as a three automobile brake lights will usually do, but you'll need a 6-volt lamp (good luck finding one!) for the +5 lead. You can build a test jig with lamps or resistors, and I always intended to but never did: it's easier to swap in a new supply. I recommend you check the existing supply for blown fuses (if there are any: some supply manufacturers don't bother) and then try a new supply. HTH. Bill -- This line of life is quick and keen The time arrives - the knife is clean I am older now and I have seen Great flames of life expire - Dave Mallett ___ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss -- Jerry Feldman g...@blu.org Treasurer, Boston Linux and Unix http://www.blu.org ___ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss
Re: Computer died
About 3 years ago I broke down and purchased an 'idiot light power supply tester'. It was cheap and I have found several dead/dying power supplies. Typically the -5 or -12 seems to go out first. It could help many folks if Blu could purchase a box of them then use them as door prises, holiday presents, etc so that anyone in the area could borrow one from a member when the time arises. It has also saved me from putting in a new PS when it wasn't warranted more than once. I'm not in the area, but I do loan out 'specialty tools' to local friends regularly. I am sure someone in the area would do the same if they have one available. I think my tester was in the $5 to $10 range back when. ___ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss
Re: Computer died
On 04/03/2011 01:03 PM, Jack Coats wrote: About 3 years ago I broke down and purchased an 'idiot light power supply tester'. It was cheap and I have found several dead/dying power supplies. Typically the -5 or -12 seems to go out first. It could help many folks if Blu could purchase a box of them then use them as door prises, holiday presents, etc so that anyone in the area could borrow one from a member when the time arises. It has also saved me from putting in a new PS when it wasn't warranted more than once. I'm not in the area, but I do loan out 'specialty tools' to local friends regularly. I am sure someone in the area would do the same if they have one available. I think my tester was in the $5 to $10 range back when. If it's an off-the-shelf component, please tell us the brand name and model number. If not, I'm sure we have enough expertise on the list to design our own. When I think about it, there _must_ be an off-the-shelf unit available from somewhere; after all, they have to test them at the factory. Bill -- He's gonna put his two cents in 'cause he's got a gun But I'm gonna put in three 'cause history owes me one - Ani DiFranco ___ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss
Re: Computer died
you might try putting a 5 ohm 1A or larger resistor across the +5V to provide some load. Sometimes switcher supplies seem to refuse to work without some load to keep the occilator doing some work. Or 12 ohm 1A or larger on the 12V. --- For some low end commercially made testers... http://www.amazon.com/HDE-Power-Supply-Tester-SATA/dp/B004J7BT28/ref=sr_1_2?s=electronicsie=UTF8qid=1301854122sr=1-2 Looks OK, and under $10 http://www.newegg.com/Product/Product.aspx?Item=N82E16899705002cm_re=power_supply_tester-_-99-705-002-_-Product is about $15 and looks like mine, but that doesn't mean anything http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=2441812CatId=1107 from Startech is about $12 Some local computer shopes may have some similar. All plus SH and Tax ___ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss
Re: How do hard drives handle bad blocks nowadays?
On Sun, Apr 03, 2011 at 05:00:27PM -0400, MBR wrote: It's now two decades later, and I'm trying to understand what's changed since then. In particular I recently cloned a laptop drive (IDE) to a new drive. When I did so, I encountered 2 bad blocks on the new drive. Based on my recollection from the late 1980s, I didn't think 2 bad blocks was a big deal because I assumed I could manually enter their addresses into the bad block list and they'd be replaced by spare blocks. But I haven't managed to find a tool to allow me to examine and/or edit the bad block list. Modern ATA (IDE) drives do this remapping automatically, and transparently to the host system--the LBA block number stays the same, but the underlying physical sector is moved by the drive firmware to a spare sector that was reserved for this purpose. Apparently, this feature can be turned on and off with hdparm -D. SCSI drives can also do this, and may be configured with this turned off by default since they are expected to be used in RAID arrays and servers that would handle this disk management on a higher level. After doing some web searches and a bit of reading on this, I get the impression that nowadays all modern drives implement S.M.A.R.T. (Self-Monitoring, Analysis, and Reporting Technology) and that using S.M.A.R.T. they all handle this behind the scenes. If that's true, then presumably the only time I should ever see a disk report a bad block is when there are no more spare blocks left. Am I right about that? The remapping only happens on write, not read. This is so that you can keep trying to read a bad block in the hopes that you might eventually recover the data with a good read or partial good read. Once you write to the sector, it then attempts the reallocation. After it is reallocated, there is no easy way to get at the old sector's data--it is effectively orphaned on the disk. (If that old sector happened to have sensitive data on it, there is now no way for you to erase it, hence the development of Anti-Forensic Splitting for use with encryption schemes such as LUKS to mitigate against this issue.) I've had drives that were stubborn about reallocating automatically with normal overwrites. I had to poke the sectors manually with hdparm: hdparm --read-sector sector-number # check if it's really bad hdparm --write-sector sector-number # repair (reallocate) bad sector If so, then the fact that I encountered write errors on two blocks on the drive suggests that the brand new drive was in pretty bad shape to begin with. Check smartctl -a /dev/foo and look for pending and reallocated sectors. I usually replace a disk once it starts getting any of those. A new disk shouldn't have any IMO, and I'd RMA it if that were the case. I do have some older drives that were given to me that have 1 or 2 reallocated sectors that I might use for scratch storage as long as the pending or reallocated counts don't keep increasing. Is there some tool that will allow me to examine the disk's bad block list? For ATA, I'm not aware of how to examine the defect list. For SCSI, you can use sdparm or sg3_utils. smartctl -a will at least tell you how many have been reallocated. I usually do the following to test suspect drives: smartctl -l selftest # look for existing test results smartctl -t short# do a quick test smartctl -l selftest # look at the results smartctl -t long # do a long test (could take an hour or more) smartctl -l selftest # look at the results Also, should I use 'dd' to test all blocks before I put a drive into service, or is there a better tool out there? Besides the above tests, I've often used dd for reading and writing the entire drive as an extra sanity test, and to force overwrites and possibly reallocate any bad sectors: dd if=/dev/zero of=/dev/foo bs=32M dd if=/dev/foo of=/dev/null bs=32M In another window: while true; do killall -USR1 dd; sleep 10; done Watch the first window for once-per-10-second status updates from dd :-) ___ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss
Re: White balance for the whole X desktop
Brendan Kidwell wrote: - my new Dell Vostro v130 with a decidedly blue backlight that's rather depressing Is this a trend? My ASUS VW266H also has a cold color temperature. Something I saw noted in several reviews. Easily noticeable when placed along side my laptop's display and a window spans across both displays. At first I found it objectionable, and tried adjusting the monitor's built-in settings, which I was never able to get to match the laptop's display. Now I've gotten used to it, and by comparison the laptop now appears unnaturally yellow (warm). What is the general procedure for creating and applying a white balance formula in modern GNOME/KDE/XFCE desktops? Any suggestions? Thanks in advance. Dan Ritter wrote: There are proprietary things that can be done with NVidia... I just recently noticed that (in Ubuntu): System - Administration - NVIDIA X Server Settings Then X Screen 0 - X Server Color Correction Not helpful in my case, as it applies to the entire X display, and not a specific monitor. -Tom -- Tom Metro Venture Logic, Newton, MA, USA Enterprise solutions through open source. Professional Profile: http://tmetro.venturelogic.com/ ___ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss
Re: Computer died
On 4/3/11 12:59 PM, Jerry Feldman wrote: I read online that 1. Disconnect the 24 pin connector from the MB 2. Short out pins 15 (gnd) anbd 16(power on). 3. Test pins with voltages. In any case with the power supply connected to the MB I was getting nothing, not even a fan. The article I read was specific to the 24-pin ATX 12V power supplies. another thing I did was to change the power cable. In any case, the multimeter read 0 when connected to ground and several other oins. I'd suggest spending a bit of time looking for a replacement (used) PS. Alternatively, eBay or the MIT Flea (2 weeks?) are your friends. I'd expect the cost to be $free to $15 total. A DMM is always handy and I think $20, or a little analog one is typically only a few bucks. As people have already said, be careful not to short out your PS by having the DMM on the wrong setting. I wouldn't worry about operating it without a load, except that you may not get any good readings. Ian ___ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss
Re: How do hard drives handle bad blocks nowadays?
MBR wrote: In particular I recently cloned a laptop drive (IDE) to a new drive. When I did so, I encountered 2 bad blocks on the new drive. What did you use to perform the clone and how were the bad blocks reported? After doing some web searches and a bit of reading on this, I get the impression that nowadays all modern drives...handle this behind the scenes. Correct. If that's true, then presumably the only time I should ever see a disk report a bad block is when there are no more spare blocks left. Am I right about that? That's my understanding. If so, then the fact that I encountered write errors on two blocks on the drive suggests that the brand new drive was in pretty bad shape to begin with. Unless the error was actually a read error during a verification step. It is possible to still encounter unrecoverable read errors. Bad blocks are only remapped on a write operation. Is there some tool that will allow me to examine the disk's bad block list? The specific location of the bad blocks may be something that only a drive manufacturer's proprietary tools can extract. Also, should I use 'dd' to test all blocks before I put a drive into service, or is there a better tool out there? See the hard drive burn-in thread: http://thread.gmane.org/gmane.org.user-groups.linux.boston.discuss/30555/focus=30559 (BTW, we now have list archives at Gmane: http://dir.gmane.org/gmane.org.user-groups.linux.boston.discuss (thanks JABR) which work a bit better than Nabble, which has gone down hill in recent years.) -Tom -- Tom Metro Venture Logic, Newton, MA, USA Enterprise solutions through open source. Professional Profile: http://tmetro.venturelogic.com/ ___ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss
Re: How do hard drives handle bad blocks nowadays?
Also, should I use 'dd' to test all blocks before I put a drive into service, or is there a better tool out there? Besides the above tests, I've often used dd for reading and writing the entire drive as an extra sanity test, and to force overwrites and possibly reallocate any bad sectors: dd if=/dev/zero of=/dev/foo bs=32M dd if=/dev/foo of=/dev/null bs=32M i use dban for new drives hosts i can take offline, or put the drive in another box. ___ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss
Re: How do hard drives handle bad blocks nowadays?
Thanks a lot for your very informative response. I'll have to read through the man-pages for hdparm and smartctl. Mark On 4/3/2011 5:57 PM, Chuck Anderson wrote: On Sun, Apr 03, 2011 at 05:00:27PM -0400, MBR wrote: It's now two decades later, and I'm trying to understand what's changed since then. In particular I recently cloned a laptop drive (IDE) to a new drive. When I did so, I encountered 2 bad blocks on the new drive. Based on my recollection from the late 1980s, I didn't think 2 bad blocks was a big deal because I assumed I could manually enter their addresses into the bad block list and they'd be replaced by spare blocks. But I haven't managed to find a tool to allow me to examine and/or edit the bad block list. Modern ATA (IDE) drives do this remapping automatically, and transparently to the host system--the LBA block number stays the same, but the underlying physical sector is moved by the drive firmware to a spare sector that was reserved for this purpose. Apparently, this feature can be turned on and off with hdparm -D. SCSI drives can also do this, and may be configured with this turned off by default since they are expected to be used in RAID arrays and servers that would handle this disk management on a higher level. After doing some web searches and a bit of reading on this, I get the impression that nowadays all modern drives implement S.M.A.R.T. (Self-Monitoring, Analysis, and Reporting Technology) and that using S.M.A.R.T. they all handle this behind the scenes. If that's true, then presumably the only time I should ever see a disk report a bad block is when there are no more spare blocks left. Am I right about that? The remapping only happens on write, not read. This is so that you can keep trying to read a bad block in the hopes that you might eventually recover the data with a good read or partial good read. Once you write to the sector, it then attempts the reallocation. After it is reallocated, there is no easy way to get at the old sector's data--it is effectively orphaned on the disk. (If that old sector happened to have sensitive data on it, there is now no way for you to erase it, hence the development of Anti-Forensic Splitting for use with encryption schemes such as LUKS to mitigate against this issue.) I've had drives that were stubborn about reallocating automatically with normal overwrites. I had to poke the sectors manually with hdparm: hdparm --read-sectorsector-number # check if it's really bad hdparm --write-sectorsector-number # repair (reallocate) bad sector If so, then the fact that I encountered write errors on two blocks on the drive suggests that the brand new drive was in pretty bad shape to begin with. Check smartctl -a /dev/foo and look for pending and reallocated sectors. I usually replace a disk once it starts getting any of those. A new disk shouldn't have any IMO, and I'd RMA it if that were the case. I do have some older drives that were given to me that have 1 or 2 reallocated sectors that I might use for scratch storage as long as the pending or reallocated counts don't keep increasing. Is there some tool that will allow me to examine the disk's bad block list? For ATA, I'm not aware of how to examine the defect list. For SCSI, you can use sdparm or sg3_utils. smartctl -a will at least tell you how many have been reallocated. I usually do the following to test suspect drives: smartctl -l selftest # look for existing test results smartctl -t short# do a quick test smartctl -l selftest # look at the results smartctl -t long # do a long test (could take an hour or more) smartctl -l selftest # look at the results Also, should I use 'dd' to test all blocks before I put a drive into service, or is there a better tool out there? Besides the above tests, I've often used dd for reading and writing the entire drive as an extra sanity test, and to force overwrites and possibly reallocate any bad sectors: dd if=/dev/zero of=/dev/foo bs=32M dd if=/dev/foo of=/dev/null bs=32M In another window: while true; do killall -USR1 dd; sleep 10; done Watch the first window for once-per-10-second status updates from dd :-) ___ ___ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss
