Dell Inspiron M5040 N5040. Computer was getting hot on left side by vent. Was reading on how to open the laptop and clean the vents and didn't get a chance to because a few weeks later the computer wouldn't boot up and gave the message: No hard drive detected.
The diagnostics test said the same, no hard drive detected and the fan passed the test.
Any help would be appreciated on where to start to fix the hard drive. I'm a amateur and willing to learn how to fix it.
Unfortunately it sounds like the drive might have failed. If this is the case, the only way to "fix" the laptop, is by replacing the old HDD with a new one. In order for you to determine that, I'd recommend that you take the drive out of your laptop and try it with a different computer by connecting either externally (via a SATA to USB adapter, external enclosure, or a docking station), or internally (directly to the motherboard via a standard SATA connection), to see if the drive is properly recognized. If it is, then you should backup any important data which you might have on it and download the HDD manufacturer's diagnostics tool to test it. If everything seems to be OK, then the cause for the problem with your laptop might be a faulty SATA port or cables.
Please let me know how everything goes.