Inspiron 7720 Randomly Enters Sleep Mode

Hello all,

I have been attempting to troubleshoot an issue involving my refurbished Dell Inspiron 7720 laptop where it will go into sleep mode at random intervals. For some reason, it will only occur while the laptop is connected to its adapter, which led me to believe that the issue was fan- and/or heat sink-related (since the processor would underclock itself on battery). I have since cleaned out the computer's vents - twice - using canned air, but to no avail. I have searched through the power settings on all of my power plans to confirm that none are set to hibernate at any time, but the issue persists. Hardware scans run through the Dell Support Center confirm that all components of the computer are operating well, and several virus scans turned up no viruses or other malware. One last piece of information: After seeing a similar issue on a different forum, I booted the computer in Safe Mode with Networking and left it running for several hours while plugged into the adapter. The computer didn't enter sleep mode at all during that time. When I booted without startup programs using msconfig, though, the computer still entered sleep mode while plugged in. I even set it to boot with all Windows programs still operating by checking the "Hide all Microsoft services" box.

I cannot seem to find a solution for this very frustrating issue. Regardless of what I'm actually doing - browsing the Internet, using Word, or even just letting the laptop run idle for a few minutes - it will enter sleep mode and won't wake up unless I close the lid and open it again. Any advice for how to solve this problem would be greatly appreciated, although one possible solution I haven't tried - updating the BIOS - was something I thought to forgo until I found some sound advice.

Thanks in advance,

DriveInDad