My wife has a nice AMD-powered Sony VAIO laptop that she has used for several years. While the Sony laptop was generally reliable, occasionally it would reboot, switch randomly between open applications (astonishing to watch), freeze and just generally misbehave. I always suspected bad RAM. I never had time to really troubleshoot it until today (July 5 2004). I am happy to say I found the cause of the problem!
The first troubleshooting fact was that the system occasionally would fail to recognize the second SODIMM RAM memory stick. The system came with 128MB, and I upgraded it to 512MB - the maximum - because the disk caching and extra memory generally makes everything work faster and better. To get to 512MB, 2 RAM memory SODIMM's are required. That means both memory sockets on the motherboard must be used. Surprisingly, the sockets are different! One (the "main" or "A" one) is very sturdy, with metal clips to hold the RAM in place. The second ("B") socket is 100% plastic except for the contacts. Naturally, when the system proved reliable with only 1 RAM SODIMM in place, I became suspicious of the B socket.
After a search on Google, I found several pages mentioning problems with this socket. The owners of those laptops were understandably quite distressed. All complained about the second socket, socket B. One person suggested folding up paper and closing it in with the RAM chips to keep pressure on them as a possible solution. I tried that, as well a cleaning and re-seating the RAM many times, and most of the time all 512MB of RAM showed up and worked. But not all the time. This weekend the system booted and showed 256MB.
Well, that's not good enough for me. After having my long-suffering wife give me permission to operate, I opened the laptop once more with the intention to fix the problem once and for all. And I did! Here is what I finally did to fix the problem:
First, I tried swapping SODIMM's and cleaning them. No success. Then I tried booting the system while I was holding down the SODIMM in Socket B with my finger - and by gosh, all 512MB showed! Now I knew I was on to something. This was a mechanical problem, not a software problem. I got out my tools and started to poke around.
First, I took a picture of the socket. I used the closeup capability of my digital camera (a Sony, how appropriate) to get a HUGE view of the pins. They looked OK so far...
Then I started poking around with a push-pin. I probed, and examined, and wiggled every single one of the 144 pins in the socket. They all looked just fine. I thought "OK, the pins are all making good contacts, but what about the socket itself?" - so I used the same precision instrument to gently push against every "leg" of the socket right where it connected to the solder pad on the motherboard. I'll bet you can guess what happened. Here is a short movie of the "Aha!" moment.
Two "legs" from the socket were not soldered to the motherboard. They would occasionally touch their contacts, and occasionally they would just sit there without making an electrical connection. The system had passed whatever Sony QA steps were necessary, and been sold. And it was defective. Well, I knew what to do. I went and got my soldering kit. I knew I had to be careful. Those legs are SMALL! First, I "improved" my soldering iron by wrapping a small solid copper wire around it to create a precision "tip." Then I tinned that wire, and used it to carefully heat each of the legs until they "flowed" into the solder on the pads. When I was done, they were rock solid.
The laptop was run through a rigorous memory test (luckily the RAM itself had not been damaged by the faulty socket) and everything worked perfectly. The laptop, and my marriage, was saved.