mystery tech

I lost my trusty western digital 250gb the other day, the drive that served as the manually mirrored backup of my desktop. This wasn’t too big a deal, as the drive was just mirroring data and not archiving anything and because I’ve recently started using mozy as a backup solution. After using syncback and extra hard drives to prevent the data loss I so fear for the last couple of years, I’ve recently been investigating online backup solutions. This was prompted by the release of Amazon’s S3 service several months ago, which has depressed the price of such offerings. Of the half dozen services I’ve investigated, mozy stands out. It’s not perfect, you can’t manage multiple computers under a single paid account and there are still some rough edges and hilarious bugs in their software, but its unlimited storage is quite appealing (if you’re on a connection with a reasonable upload) and they offer good encryption options.

mozy has a free version of their service with a capacity of 2gb and for 50usd a year you can upload as much as you can. The emphasis in the last sentence should be placed on “as much as you can” most residential high speed connections are skewed towards downstream, and many have very poor pstream, mozy seems to be banking on most people not having the patience to spend days uploading the gigs they presumably want to backup or that this restriction will keep people from abusing their “generosity.” I’ve pushed about 60gb to the service so far, which is about the amount of data I would be very upset about losing and everything has worked fine so far.

While my desktop, using the unlimited plan, hasn’t had any major problems, I ran into a stumbling block using mozy to backup my laptop. I’m using a Thinkpad t43 dual booting XP and Ubuntu thanks in large part to the excellent Thinkpad linux documentation available on Thinkwiki. As a result of the dual boot, the hard drive configuration is a little strange on the thinkpad.

sda6 is the volume that both the windows and ubuntu installations share access to, it’s formated in ext3, which windows can’t read or write to natively. That’s where the Ext2 Installable File System For Windows comes in. With this extension installed in windows, sda6 shows up as drive D.

Everyone is happy! The files on the D drive can be accessed by both the Ubuntu and Windows installations. Unfortunately, mozy can’t read the D drive, and therefore can’t backup it’s contents. This presents a real problem, as this setup is fairly ideal for getting work done on the thinkpad, but mozy isn’t likely to support a storage schema this obscure.

After some pondering I’ve come up with a solution I’m happy with. It occurred to me that anything on the Thinkpad that is worth backing up is also relatively sensitive data, so in an attempt to solve both problems at once we turn to truecrypt. A highly robust encryption package, truecrypt works with encrypted volumes that are mounted within either windows or linux systems. In other words, using truecrypt a file is created, the encrypted volume, which can then be mounted and unencrypted, so it appears as another hard drive. truecrypt is evidently more interoperable than the Ext2 File System because mozy recognizes a truecrypt mounted volume and can backup it’s contents.

So, after creating a truecrypt volume, called “truecryptfile” and storing it on the D drive (where both the Ubuntu and Windows installations will have access to it) we can mount it to the I drive. So even though the truecrypt volume is stored on the D drive, which mozy can’t read, when the truecrypt volume is mounted as the I drive, mozy can read it.

Setting the volume to automount on boot will prompt for a password when starting the system.

mozy can see the I drive! Success!

This workaround is slightly strung together, using an extension of the windows file system to mount an ext3 volume and then using truecrypt to mount another volume, which is contained on the ext3 volume and then having mozy read off that. Despite the counterintuitive approach, everything on my laptop is encrypted, backed up and organized.

So, I abused the hell out of my camera. It rode in my back pocket as I stumbled through the last few months and I ended up smashing the screen on my Canon SD400 (sometimes known as the IXUS 50.) It was not the camera it once was. Note the dents, scratches and the fact that all the coloring around the optics is gone. Despite broken screen, I’m pretty happy with the amount of abuse it absorbed. The camera still worked and took pictures despite not having a working screen, but the optical viewfinder was all clogged with dirt and I was attempting to navigate the menus from memory and without feedback. It sucked.

This was sad, so I started googling for the possibility of a user replaceable screen and while what I found certainly voids the warranty faster than throwing the camera under the wheels of a moving van, it worked. Nuts to you warranty.
Andy Ozment has a nice (if google adword covered) multi-model write-up about repairing the screens, but no pictures. I *guess* this is an understandable side-effect of writing a guide on repairing a camera, many people might find it tough to photograph the repair while trying to repair the object that would be used to take photographs. I am not one of those people. Oh, now is as good a time as any I guess:

Perform at your own risk. This shit WILL void your warranty, oh god don’t sue me

Here we go.

• I got a new screen from Foto Geeks it came in a silly little box and seemed tiny for costing 65bux.
• From reading on the internet I took a guess that my backlight was *NOT* broken, the chief indicator of its well being was the glow it gave off through the shattered screen, this is good. I don’t know where you can order a new backlight, but I’m pretty sure you could replace it in nearly the same method I use here
• I used two Craftsman Professional screwdrivers, a flat head 3/32×2-1/2, and a philips 00×2-1/2. I love these screwdrivers ’cause I’m pretty sure you could prison stab someone with them and my Dad gave them to me. (thanks Dad)
• You’ll also need Scotch Tape, a Post-it note and scissors.

First, remove the battery and memory card, I guess you should also be worried about static discharge frying the camera, but I did this repair whilst wearing socks on the carpet, I think you’ll be fine. I’m fairly sure that static electricity doesn’t really exist.

Here’s the unboxed replacement SD400 LCD screen. I tried to keep the new screen as dust free as possible so as not to trap any crud under it during installation. Determining the orientation is going to be important later, so notice that the screen has two distinct sides.

There are six screws on the exterior of the camera, REMOVE THEM!

When all the screws are out, pull the two overlapping halves of the camera apart, being careful as it is possible to bend the metal.

Parts that will fall out:

• Silvery plastic circle thing.
• Rectangular silver mount for the wrist strap
• Buttons

I did a powerup here to check that I hadn’t messed anything up at this point, and ’cause I didn’t have a picture of the screen in all it’s glory.
This may have been a shock risk or just stupid, I don’t know.

At this point I installed an InvisibleSHIELD on the new screen while it was still outside the camera

Removal of screw number 7, this screw is a different size than the others, so don’t get it mixed up.

This is one of the hardest parts of the whole procedure. The backlight and LCD are held together with a series of metal clips that have to be freed before you can replace the screen. I used a small flat head screwdriver to wedge in between the two and try to get the claps undone. This is also the part I have the worst pictures of. The goal is not to get the LCD off right now; it’s just to get it detached from the backlight.

When it comes loose, you’re going to want to slide it to the left before you lift it up like the pictures shows. There’s a few little catches that you don’t want to break off, but sliding the screen out a little bit before lifting should avoid this.

Flip the camera over and using the screwdriver, lift up the small black plastic gate holding the ribbon cable in, and pull it out.

Now comes the really unpleasant part. The ribbon cable is threaded through the internals of the camera, if you pull it free, it’ll be very hard to get the new cable back through. That’s where the tape and Post-its come in; you can use them to make yourself a little retrieval cable and pull both the ribbon cable and the post-it through. You can then use that same bit of paper to guide the new ribbon back through.
Make sure that the new screen is going on in the same orientation as the old one; there likely won’t be room to turn the ribbon over when you get it threaded.

Here’s the old screen with retrieval post-it attached and ready to go

Now the old screen, ribbon, and post-it have been pulled through.

Transfer of the post-it from the old screen to the new one, with the new screen in the correct orientation

Threading of the new ribbon through the cameras internals, this would be quite hard without the post-it already in place as the path inside the camera goes up and down. Also consider applying tape to both sides of the ribbon/post-it interface to make sure nothing gets snagged inside the camera.

When you have the ribbon cable back through, reseat it very deeply into the channel and lock the gate back down. Then give the camera a power on:

Counter-Terrorists WIN!

Put it back together and do a little dance, that wasn’t so bad.

(that’s a picture of my closet.)