First post of 2011! I hope all of you had a happy new year. For this year’s first post, here is another article documenting my attempt to repair electronics, and this time it’s for the video card of the six year old Athlon XP PC that I built myself. Similar to my last repair article about LCD monitors, the video card was also afflicted by the capacitor plague, and thus I had to get out my soldering iron once again and replace some capacitors. I’m no expert at repairing electronics, so this just goes to show what you can do with a little bit of research, some inexpensive equipment, and the courage to try.
A bit of unimportant history: I built the Athlon XP desktop six year ago and I’ve used it until four-five months ago when I left home for grad school. I bought myself a new laptop, and the old PC was passed down to my mother who was using an even older Compaq that was terribly slow because it didn’t have enough memory. My desktop was old, but it had 1GB of RAM and was fine for web surfing, word processing, and even Photoshopping, so giving it to my mother would hopefully save us from having to buy another new computer.
So after I left for grad school, the PC worked fine for about a month, but then it started acting up. The symptom was sometimes when turning on the computer, the fans would spin and the lights would light up, but there would be no beep and no image on screen. After attempting to turn it on several times, the PC would boot. The symptoms kept getting worse until one day the computer just wouldn’t boot no matter how many tries. My mom needed a computer to use, so my parents bought a new desktop, but they kept the old PC around so I can take a look at it when I returned for vacation. If I can fix the computer, my parents can keep it as a backup machine or for guests to use. If I can’t, well it’s a six year old computer so it has served its purpose.
Starting the repair process, I tried turning on the desktop for the first time, and as my parent indicated the fans and lights powered up, but there are no beeps and no image on screen. No beeps during boot probably indicates a hardware problem. I was suspecting either the motherboard or the video card, and my guess was probably some bad capacitors. Both motherboard and video card were bought six years ago, and those were the days when computer parts were built using bad capacitors. Besides that fact, capacitors are also the only thing I know how to replace right now. I checked the motherboard for bulging, leaking, or exploded capacitors, but all of them seemed fine with flat tops. I then removed the video card for inspection, and lo and behold four capacitors were bulging with one of them having leaked a little bit of brown substance. Just to make sure that the motherboard was okay, I turned on the computer without the video card, and as expected the computer did the annoying long beeps that indicated that the video card was missing. I couldn’t say for sure if the capacitors were the only things wrong with the computer, but I knew they were causing some problems given the state they were in.
With one problem identified, it was time to collect the parts. The four bad capacitors were all 6.3V, 1500uF units. Unlike my LCD monitor repair, I didn’t have this kind of capacitors on hand, so I had to spend money to buy them. There is no guarantee that replacing the capacitors would fix the computer, but these capacitors are cheap so it was worth a shot. It’s better than spending $40 to buy a new (but obsolete) AGP video card for a computer that’s probably worth less than $40 these days. I bought five new capacitors from a local electronic parts store for about $4. I only needed four, but bought one extra just in case of any screw ups on my part.
With the parts ready, it was time to bring out my $10 soldering iron to do the job. The circuit board of a video card is supposed more delicate than the inverter board in a LCD monitor, but since the video card is so old it’s not worth getting a better soldering iron. The capacitors weren’t too small and they were far away from other components, so I didn’t really need a fine tip. Removing the old broken capacitors was probably the hardest part. I removed them by heating the holes from the underside of the board and wiggling the capacitors. As each capacitors has two leads, I heat one hole, wiggle the capacitor a bit, then heat the other hole and wiggle the capacitor out a bit more, and then repeat until the capacitor was out. It took a while to remove all four capacitors, but eventually they all came out.
It was now time to put the new capacitors back in. The new capacitors are much taller than the old capacitors, but the width and spacing between the leads are the same, so they fit right in back into the holes in the circuit board. I clipped the leads first and then try to solder them back in. Putting new capacitors in is the exact opposite of removing old capacitors: heat the holes and wiggle the leads into the holes. I didn’t even have to use extra solder because the holes still had plenty of solder in them, and putting the capacitors back in took less time than pulling them out. As always with electrolytic capacitors, I had to make sure that I lined up the polarities correctly. The stripped side of the capacitor is always the negative terminal.
Now that the capacitors have been replaced, it was time put the video card back in and try to boot the computer up. I pressed the power button, and the computer gave the long beeps indicating no video card. I wiggled the video card a bit, but got the same result. Unwilling to give up just yet, I replugged the video card, and this time the computer booted up as normal, and the screen had an image. I used the computer for a little bit and it seemed to be fine, so it looks like the problem is solved.
Despite my shaky hands and cheap equipment, I have another successful repair under the belt. Compared to the LCD back light repair, I had to replace more capacitors to fix the video card, but accessing the video card was a lot easier than accessing the inverter board of the LCD. I’m glad to have fixed the computer, and hopefully the repair will extend the life of the desktop for a few more years. The PC has misbehaved several times on me and my family, but it is the first computer I’ve ever built and I’ve used it for six years, so there is a little bit of an emotional attachment. If we can make it run and find a use for it, it’s better than sending it to recycling. Thanks for reading.