Archive for the ‘hardware’ Category

Dell Laptop A/C Power Cable Images

Saturday, February 12th, 2011

After a month of off-and-on power issues with my Dell Inspiron 1525 Laptop, the A/C power adapter finally stopped powering the laptop. It had stopped being identified as an authentic Dell charger a couple months ago, as I wrote about here.

I was quite certain that the power cable had broken internally due to the constant flexing.  It’s happened on almost every laptop that I’ve owned.  Slightly jiggling the power cable approximately where it flexes during natural use would cut power to the laptop.  Putting little stresses in the cable with twist ties would sometimes make the power work for a few days.  These fixes were really temporary – they only  put off the inevitable complete failure.

The options are to buy a band new authentic Dell PA-12 (or higher rated) power adapter for more than $100 directly from Dell, buy a 3rd party “compatible” charger for about $20 from eBay or DealExtreme.com (but I don’t trust 3rd party items when they plug into the household power… I don’t like fires), find a used authentic charger, or cut the cord and solder things up again.

So, the other day I cut the cable.  Here are a couple pictures that might make it easier for anyone who needs to do this in the future.

 

 

Dell Laptop Cable Inside - Cable Half

Dell Laptop Cable Inside - Cable Half

 

 

This is the cable half of the cut. You can see the top of the magnetic field minimizers… the name of which escapes me right now. There are three conductors. The tiny one in the center is for the chip in the PSU that tells the laptop whether or not the charger is an authentic Dell device – in my case, this broke months ago, when the Dell battery stopped charging – even after re-soldering, this charger still does not register as authentic; there must be another break further up the cable. Then two more layers of conductors.  I’ve covered off the outermost in red tape as I prepare to re-solder things together.

 

 

Dell Power Cable - Plug Half

Dell Power Cable - Plug Half

 

 

This is the plug half of the cut.  I’ve removed some sort of epoxy or hot-glue that held the above wires together in the form that fit inside the plastic shroud.  I think it’s hot-glue because it seems to hold the shroud over the plug.  I managed to pull the shroud off without cutting it, by running a unrolled paper clip around the edge, breaking the glue’s bond a little at a time.

As I expected, the outermost strands had all broken from repeated movement. You can see the random fraying in the strands at the top left.  Also, the center wire was clearly detached.  The 2nd conductor, white, on the right, was OK.

I’m not very good at soldering to plugs.  I tend to melt the plastic badly before getting the metal parts hot enough to solder.  So, instead of disconnecting the stubs left over in the image above and soldering directly to the plug,  I decided to trim them up and splice the wires together and inch or so from the plug. The middle wire I soldered directly.

Then I used hot glue to keep things from flexing, then wrapped it all with  electrical tape.  The end result is passable, but not pretty, so I won’t post a picture. And my Dell lives for another day… I’m using it to type this post now!

Comments appreciated!

 

 

Today’s Edition of “Always do your backups” is a Win7 Netbook

Friday, January 14th, 2011

I was not pleased to see that the new netbook that I mentioned in a previous post, did not come with restore DVD’s.  However, I just realized that since there is no DVD drive, most regular people wouldn’t know what to do with restore DVDs.

Anyway, I decided to make a full disk image backup, in case the drive in the netbook crashes badly.   Hard drives have moving parts, they all die eventually, the only question is if you have retired the computer before it goes.

Without restore DVDs, my next thought was to use  the Windows 7 built-in disk image backup.  I re-discovered that this feature does not back up over  network drives*. You’re supposed to use  an external USB hard drive, which is OK, given the price of external drives. But since I’m not familiar with the Win7 backup tools, and in particular, I can’t figure out if it will backup the hidden partitions that contain the original install files for Windows and the rest of the software bundle, I decided to fall back on my favorite disk image tool, G4L.

I have used G4L (http://sourceforge.net/projects/g4l/) for clients and personal use for years, so I strongly prefer to use it. Without a DVD drive, I needed to make a bootable USB thumb drive.  That was surprisingly easy.

To create the bootable USB drive, I  followed the instructions here: http://radified.com/cgi-bin/yabb2/YaBB.pl?num=1224777260/0

As I type this, G4L is busily sending a perfect disk image of the netbook to our on-site FTP server.  It’s not quite a factory image (the netbook has been lightly used),  but it’s close enough.  Plus, the real restore partition is being backed up in case I really need to return it to factory settings.

* There are some tricks to do Windows 7 disk image backups over a network, one using Virtual drives feature of Win7, and another using iSCSI… but I digress.

Are 5400 RPM drives more reliable than 7200 RPM drives?

Thursday, November 11th, 2010

Bottom line, I don’t have an answer.  But, if I had to bet, I would bet yes.

I skimmed many of the top 10  pages that came up on a Google search and found a lot of hand-waving and very little actual data.  So, I decided to post my own theory here!

Even if there was data, it doesn’t matter.  The differences between various models of drives, or different factories, or different years from the same manufacturer, are probably larger than the difference from spindle rotation speed.  Every brand of hard drive has head crashes, and generally, it seems proportional to market share.  Every once in a while a company has a bad run, and it’s happened to almost all the brands at one time or another.

I decided to replace the crashed hard drive of my home “server” with a 5400 RPM Western Digital Green drive.

My theory is that almost all the components that go into a hard drive are designed and spec’d for 7200 RPM drives.  I can’t imagine a hard drive manufacturer producing parts that are only stable up to 5400 RPM.  The engineering and machinery costs are far higher than the price of the bits of metal and chemicals.  Thus, if the majority (or even all) of the parts are designed to run at a faster speed, running at a lower speed will generally be better for the drive life.

Besides, for this particular machine, speed isn’t that important, plus saving a few watts in power is an added benefit.

What do you think?

 

Dell Inspiron 1525 – problems getting Bluetooth stereo (A2DP) working

Friday, July 30th, 2010

I pulled out my old Bluetooth A2DP headphones and tried to get them to work with my Dell Inspiron 1525 today. As usual, getting everything working wasn’t as easy as it was supposed to be.

I could get the headset to pair correctly. It also worked fine in “handset” mode – i.e. to make phone calls. But I wanted to listen to music and my device wouldn’t “connect” to “Bluetooth Stero Audio”. Annoying.

I’m not 100% sure that the problem was generic to my laptop model, or specific to my computer due to some software incompatibility. After some web searching, I decided to try downloading and installing the Bluetooth drivers from a more current Dell model, the Vostro 1401. This uses uses the same Bluetooth module, the Dell 355. Things seem to be working so far.