I had this Toshiba Satellite Pro P6100 laptop sitting around. It had been tested some time ago, and it had errors in the video graphics memory. I had used VMT which is a Video Memory Stress Tool, to run diagnostics on the video graphics memory .
This is what the screen looks like. What we see at the top of the screen with the greenish lines are artifacts on the display due to these memory errors. Now the memory errors are not stable, they appear at different addresses and affect different bits, so it could be a graphics processor problem or a memory problem. This laptop had a separate card which contains the graphics processor and its two memory chips but also interfaces to the keyboard, mouse pointer buttons and the system board. Due to my previous success with using my SMD Rework station to reflow a laptop system board, I thought I should try this again.
I removed the graphics add-on board, and taped up the areas that I did not want to heat up. I also attached a thermocouple temperature probe, just like I had done previously.
I worked my way around the board, heating the three chips gradually, and then concentrated first on the graphics processor, and then afterwards on the two memory chips. After letting it cool down, I then reassembled the laptop and was rewarded by a clean display with no signs of artifacts.
Another successful “Reflow.IT“. I suspected that due to the nature of the problem where the memory errors occurred at different addresses and different bits that it was an intermittent connection problem with the chips. The reflow helps to melt the solder and let it solidify “hopefully” making good contact on all the chip connection points. It looks like it worked. Now what do I do with a laptop with a Pentium 4 and 512MB of ram. It runs Windows XP and has a 40GB disk drive and has a serial port on it, which is quite sadly lacking from most modern day laptops.