Several days ago I noticed it was running much hotter than normal. I shut the computer down, unplugged from power, and inspected the inside of the computer. There was a substantial amount of dust built up inside the fan and heat sink. I removed the protective shroud around the heat sink, removed the heat sink, and vacuumed out the dust from the fan/heat sink. I noticed that the thermal compound looked dry/patchy, but did not replace the compound. (This is the factory original compound)
With the computer re-assembled I attempted to start it with mixed results. On the first attempt, nothing happened. On the second attempt, the computer sounded as if it was booting up, but my monitor did not display any info. Now, the computer boots as normal, I am able to log in, and get to the desktop which shows my programs/files still in tact. However, just after reaching the desktop the computer will shut down and the power light will turn orange/blink. The timing varies slightly on this, but it consistently happens just after logging on/seeing the desktop for the first time. This has happened several times, start-up, log-in, and reaching the desktop just before it shuts down again.
I tried to start-up the computer twice after this but was unsuccessful; the fans for the processor and the power supply spin for an instant, then the blinking orange power light reappears. No start-up. I have also noticed that the orange aux power l.e.d. on the board is lit up.
Any thoughts on what might be causing this? (Again I only removed the heat sink and it's protective shroud.)
Is it as simple as applying new thermal compound?
Could there be an excess of static inside the case from vacuuming?
ALWAYS, without fail, remove (use isopropyl alcohol), then replace, the old thermal compound any time you remove a heat sink. Never reuse old thermal compound. And, you should never use a vacuum cleaner inside the case (static buildup will kill electronics). Instead, use a soft bristle, anti-static brush to loosen the dust/dirt and blow it out with a can of compressed air. If you want to keep the vacuum running in the vicinity to catch the dust cloud that's fine, just don't go poking around inside with it.