Newbie here. I decided to dive into the guts of my machine today. I removed the insulation pad from my heat sink with kerosene, and removed the remaining residue from the CPU with rubbing alcohol (wouldn't try the kero on the CPU, it doesn't evaporate well) OK, here goes. I did the pencil trick on my AMD Duron 700. The system booted seemingly normal except the monitor would not come on, black screen. I then changed the jumper setting on the motherboard from 100 to 133, this only worsened the situation as it wouldn't boot correctly at all. I went back and removed the CPU and erased the pencil tracks and set the jumper back to 100 MHZ. Everything is back to normal now. The question is, what am I missing? What did I do or not do correctly? The motherboard is a Compaq Presario 5WV232 except it is fed by a 300w power supply now. 384 MB RAM and Redhat Linux 7.2. Everything else is stock.