Tuesday, August 04, 2009

Solders in tight places

My laptop has had a couple of problems since I bought it in September 2007. Right off the bat, I didn't like that you could only adjust the volume through the software, requiring Windows to be running. This was an unwelcome change from my 2003 Toshiba laptop, which had a little wheel on the side so you could manually adjust the volume.

In April '08, the hard disk died. While this was stressful and took me a month to eventually deal with, Dell's warranty support was very helpful and got my drive replaced quickly. I was able to recover the information off of it, and since then I've always* backed up my hard disk (*read: I backed up once right after the incident, and have never crossed "back up" off my to-do list since then).

Earlier this year, my laptop battery reached the end of its life, and would no longer hold a charge. I had to weigh getting a new laptop versus simply replacing the battery.

If I bought a new battery, it would be about $200 instead of $600 (neither amount I was pleased with spending), and I wouldn't have to reinstall all my programs or worry about Windows Vista or Yogourt. But it also meant that I'd have to live with the other problems my laptop has.

A while ago, sometime after the one-year warranty expired, the audio jack started thinking that there was always something plugged into it, even if there wasn't. If I had earphones plugged in, audio went to the earphones. If I didn't have them plugged in, it still thought I did, so it didn't play sound on the onboard speakers. I eventually learned that if I stuck a mini jack cable in partway and used strong rubber bands to pull it sideways, it would work. I also couldn't rip records to mp3 because the line-in wasn't reliably carrying both channels.

This audio problem had a number of influences on my battery-or-new-laptop decision:

- I wouldn't be able to sell the Dell as easily

- A new laptop (i.e. one with working speakers) is that much more attractive

- While it's faster than my 2003 Toshiba laptop with the broken screen (which I use as my 'desktop'), it doesn't have audio to complete the audio/visual experience, and it doesn't have a parallel port for my laser printer.

I decided that if the price was under $200 and if I could get it by the end of the following week, I'd order the new battery. I phoned them up and spoke to some guy in southeast Asia who assured me that I'd get it by the prescribed time. Of course, he's from one of those cultures where customer service only goes so far as telling the customer what he wants so he'll buy the thing from you, and not a culture where it matters if this information is true.

On Friday of the following week, Gabby at Dell customer support got a call from an irate customer. I had been assured that I would receive the battery by the end of this week, and it has not arrived yet. Gabby told me it was shipped out that day, meaning it wouldn't arrive until the next business day--Monday--which is precisely the kind of waiting I deliberately tried to avoid. If I had known it would take that long, I would have bought a new laptop, and not from Dell!

So fast forward to tonight, and I plug in my earphones, and I hear a quiet electronic "click" and get no audio. I try jiggling the jack and putting pressure on it, with no luck. My audio is dead.

On top of this, I notice that the audio jack is very hot, which is quite unusual. I figure there's probably a short circuit, meaning the laptop's not safe to use.

Time to open 'er up.

I had previously opened up the laptop and gotten to the sound jack, only to discover it was hardwired into the motherboard. If it were connected by a plug, I'd have ordered a new one long ago to swap it out. But it isn't, so I couldn't.

And it's a long process to get that far into the machine. Dell has excellent documentation for disassembling its machines, including step-by-step instructions on how to get in to the motherboard (and how to get it back together). However, it still took me about an hour to get inside. While I had it open, I cleaned some of the parts of dust and other dirt.

Diagnosing the problem was hard. There are contacts that push against each other when you put the plug in, and I saw that the ones for the audio jack weren't making good contact. I did some fiddling around and got the contact working, but there was a second one in an angle I couldn't see, and I was hoping that it wasn't a source of the problem, because I didn't want to open this thing up again.

But the loose contact wasn't the only problem. I tried to inspect the connection to the board, and it was tough. The contacts are very small, 0.6mm wide. The solders are even smaller. I had a magnifying glass, but I couldn't get it close enough without blocking the light.

So I used my camera's macro mode to take a close-up photo, which I could then zoom in on the camera's screen to investigate.

This, too, was hard, as the lighting was poor, and it was hard to get the camera to autofocus at the right distance. I held up a bright bike light to the board, and took the photo top-down to make focusing easier. Unfortunately, a top-down angle also makes it hard to inspect the solders.

Nevertheless, I could tell that the all three solders in the leftmost cluster were broken.

So I knew I had to solder them back together. I plugged in my soldering iron and put some electrical tape over the neighbouring parts so that I didn't accidentally melt them off, as I was working with very small bits at a very tight angle. The furthest contact was easier, because there was about 0.3mm of space next to it, whereas the other two contacts were less than 0.2mm apart. That big black tarp on the right in the photo is the electrical tape.

I appeared to be successful with the first one, but the other two were too close together, and I would have difficulty trying to get a glob of solder on them without accidentally soldering the two of them together, which would be very tough to fix.

I tried anyway--without the glob of solder on the end of the iron--and took a photo to see if this made any progress.

Success! There was enough original solder on the contacts that I just had to melt it and it reestablished contact on its own (much more elegantly than my fix on the far one).

Of course, success wouldn't be conclusive until I get the machine back together.

Midway through reassembly, I find a screw that belonged somewhere inside. I taped it under the keyboard for future consideration (I am NOT going to take it back apart now!), and screwed the keyboard back into place. It's late, goddamnit.

When I turned on my laptop, I got onboard sound, for the first time in months!


Let's hope it stays that way.

- RG>

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