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Repair Acer AspireOne 532H Netbook Screen

The Acer AspireOne 10.1″ netbook is a handy secondary computer to have around. It’s quite capable of browsing the web, email and viewing photos. Most casual users could likely happily use it as their primary machine. Tablets have all but killed this market, I’m hopeful that the Google Chromebook will bring help back this form factor.

Unfortunately being a secondary computer means that it gets left around (on the floor) and stepped on. This was the sad fate of this particular netbook. It turns out that replacement screens are relatively inexpensive making it well worth fixing. First step was to boot the netbook connected to an external monitor to confirm the resolution of the panel and make sure nothing else was wrong. Armed with that, and a compatibility list I was able to find a good price for one from a Canadian seller on ebay. Shipping was very fast and the screen came well packaged: boxed and inside a padded envelope.

Disassembly is quite easy, this YouTube video covers it quite well. Below you’ll find some photos and my notes on the process.

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DIY Repair Nikon Bayonet Mount

Nothing is quite as sad as a broken bit of equipment. Sadder still when it’s a fairly expensive component and repair costs at a shop are hundreds of dollars. This Nikon DX AF-S 18-55 VR lens took a kid + dog caused tumble to the ceramic floor, it was mounted on the camera and the impact busted the plastic mounting tabs (if you look closely at the picture above you can see the busted tabs).

On the bright side, if the tabs hadn’t given way something else might have taken more impact and broken. By carefully holding the lens on the camera it was possible to verify that it appeared to still be working fine.. if only it would stay mounted. Glue might have worked, but I wasn’t brave enough to slap a little glue onto an expensive lens. A few calls to local camera shops left me a bit shocked at the cost of repairs, it was not worth repairing as a new lens was almost the same price. What I found interesting was that even buying the parts from a local shop wasn’t an easy option, it seems Nikon is making it more difficult for repair shops to get parts.

I did find some reasonable web resources out there giving step-by-step information on replacing the mount. You can also pick up the required part via ebay. It turns out you can order the part directly from Nikon as well. Their email support was responsive within 24hrs, and I was able to call them directly with a credit card and have it shipped to me in a couple of days.

So with the correct part in hand, it was time to take things apart. I used both #0 and #00 Phillips screwdriver bits, my fingers and patience. I’ll avoid duplicating the instructions found elsewhere and simply provide a few comments on my experience:

The screws are very, very small. You’ll want to work in a brightly lit area with care not to lose any.
When reassembling and I was reaching with my fingers to get the tab with the electrical contacts from where it rested “inside” the lens, I managed to get a fingerprint on the lens. Using more caution you can avoid my mistake.
I messed up the first reassembly, the bayonet part of the new mounting ring needs to be in the ‘right’ place. Refer to the photo below: At about 10 o’clock there is a small metal pin. The bayonet should be clockwise side of that (say 11 o’clock). Everything fit, but the lens didn’t operate correctly on the camera.
Those metal rings, you don’t want to move them if possible. The good news is that three of the screws you take out fit down through those rings, making it relatively easy to get lined back up if you move them a bit.

I’d never done this type of repair before and I was done well under an hour total. The second re-assembly was 15mins tops. Total cost: $10 + $15 shipping direct from Nikon Canada. If you opt for the ebay route, you may need to transfer the bayonet metal part from the original as most of them only offer the plastic ring – the official part is complete.

Add drive to RAID5 on Ubuntu

Some time ago I migrated from a RAID1 setup to RAID5, this was on the minimum 3 drives. At some point this summer I spotted a good deal on a matching 1TB drive to what I had in my array and bought it. My purchase sat in my desk drawer for a month (or two) then I finally got around to installing it into the server. At least another couple of months went by until I got to adding it to my array – it turns out to be really simple and I’m kicking myself for dragging my feet.

With any hardware upgrade (specifically drives) it’s a good idea to capture what the system thinks things look like before you make any changes. For the most part Ubuntu talks about UUIDs for drives, but a couple of places (at least in my install) use the /dev/sd*# names and can trip you up when you shuffle hardware around. Capturing the drive assignments is simply a matter of:

$ sudo fdisk -l | grep ^/dev

Post hardware installation I was surprised at how much of a shuffle the /dev/sd*#‘s changed around. I was glad I had a before and after capture of the data, it also let me identify the new drive pretty easily.

Early in my notes I have “could it be this simple?” and a link to the kernel.org wiki on RAID. It turns out that yes, it really is that simple — but you do need to follow the steps carefully. I did also find an Ubuntu Forum post that was a good read for background too.

The new drive I had temporarily used on an OSX system to do some recovery work, so fdisk wasn’t very happy about working with the drive that had a GUID partition table (GPT). It turns out parted was happy to work with the volume and let me even change it back into something fdisk could work with.

I puzzled over the fact that this new drive wanted to start at 2048 instead of 63, I was initially under the incorrect assumption this had something to do with the GPT setup that I hadn’t been able to fix. Consider two basically identical volumes (old followed by new)

$ sudo fdisk -l /dev/sdb

Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes 255 heads, 63 sectors/track, 121601 cylinders, total 1953525168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00000000

Device Boot Start End Blocks Id System /dev/sdb1 63 1953520064 976760001 83 Linux

$ sudo fdisk -l /dev/sdc

Disk /dev/sdc: 1000.2 GB, 1000204886016 bytes 255 heads, 63 sectors/track, 121601 cylinders, total 1953525168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes Disk identifier: 0x00000000
Device Boot Start End Blocks Id System /dev/sdc1 2048 1953525134 976761543+ 83 Linux

I’ve highlighted the key differences in bold, you can see the physical sector size is 4096 vs. 512 and that is the reason for the different start position. Ok, diversion over – let’s actually follow the wiki and get this drive added to the RAID array.

Start by looking at what we have:

$ cat /proc/mdstat Personalities : [raid6] [raid5] [raid4] [linear] [multipath] [raid0] [raid1] [raid10] md_d3 : active raid5 sdf1[1] sdd1[0] sdb1[2] 1953519872 blocks level 5, 64k chunk, algorithm 2 [3/3] [UUU]

So, my RAID5 array is /dev/md_d3, and I know my new drive is /dev/sdc1 after my parted/fdisk adventure above.

$ sudo mdadm --add /dev/md_d3 /dev/sdc1

Now we look at mdstat again and it shows we have a spare. This is honestly what I should have at least done with the drive immediately after installing it – having a spare lets the RAID array fail over to the spare drive with no administrator intervention.

$ cat /proc/mdstat Personalities : [raid6] [raid5] [raid4] [linear] [multipath] [raid0] [raid1] [raid10] md_d3 : active raid5 sdc1[3](S) sdf1[1] sdd1[0] sdb1[2] 1953519872 blocks level 5, 64k chunk, algorithm 2 [3/3] [UUU]

Next we grow the array across the new device

$ sudo mdadm --grow --raid-devices=4 /dev/md_d3

You can peek at /proc/mdstat from time to time (or use the watch command) to monitor progress. This may take a while.

Once this is done, don’t forget to modify /etc/mdadm/mdadm.conf as per the wiki: “To make mdadm find your array edit /etc/mdadm.conf and correct the num-devices information of your Array”

At this point we now have our data spread across more drives, but don’t have a larger volume. We need to resize the volume to take advantage of the new space. It’s recommended you do the resize with the RAID5 volume unmounted (offline). I set about to do this and hit problems unmounting the volume: this turned out to be samba holding on to the volume, turning that service off fixed things.

Then I hit a show stopper, the resize2fs command failed:

$ sudo resize2fs -p /dev/md_d3 resize2fs 1.42 (29-Nov-2011) resize2fs: Device or resource busy while trying to open /dev/md_d3 Couldn't find valid filesystem superblock.

Huh? This is something I’ll one day sort out I suppose, but it really beats me what is going on here. You can resize RAID5 while it’s online too, it’s slower and a bit scarier, but it works.

$ sudo resize2fs /dev/md_d3 resize2fs 1.42 (29-Nov-2011) Filesystem at /dev/md_d3 is mounted on /stuff; on-line resizing required old_desc_blocks = 117, new_desc_blocks = 175 Performing an on-line resize of /dev/md_d3 to 732569952 (4k) blocks.

This was followed by a few moments of terror as I realized that I was doing this over a SSH connection – what if the connection is lost? Next time I’ll use screen, or nohup the process.

It was neat to watch the free space on the drive creep upwards. It was running at about 1Gb every 2 seconds. Once this finishes, you’re done. My RAID volume went from 1.9T to 2.8T with the new drive.