This started after someone blew canned electronic duster into the computer while it was powered on. Since then, putting the PC to sleep sometimes causes a complete shutdown instead, followed by a restart when I press the keyboard and a Windows sign-in prompt. After resetting the CMOS battery for a minute or two, the issue temporarily stopped, but later the computer began repeatedly going idle, attempting to sleep, shutting down, restarting, and repeating the cycle about every 10 minutes. Reliability Monitor only reports that Windows was not shut down properly. I checked the cables, RAM, and graphics card, and after power-cycling the system, normal sleep seems to work again while idle-triggered shutdowns remain a concern. What should I check to find the cause?
2 Answers
Canned air by itself usually should not cause this, unless something was physically loosened, moisture was left behind, or a component was stressed while the fans were spinning extremely fast. Reseat the RAM, graphics card, and power connectors, and inspect the motherboard and fans for anything out of place. Also make sure the computer was fully powered off before using compressed air in the future.
The generic reliability message only confirms that the system lost power or crashed; it does not identify the cause. Check Event Viewer around the exact shutdown times, especially the System log, for Kernel-Power, bugcheck, driver, or power-management errors. Also review the sleep and power-plan settings to confirm the PC is actually entering sleep rather than shutting down or restarting because of a crash.
Reliability Monitor only shows “Windows was not properly shut down” for each event. After a full power cycle, normal sleep appears to be working, but the problem still seems to happen when the computer sits idle.
I checked the cables, RAM, and graphics card and did not notice anything loose. I suspect the timing may be related, since the problem began right after the dusting, but I cannot say for certain what happened.