Not a lot of testing required here, most of the time they work or they don’t. In the case of cd burning issues, ensure you try different media if you are having problems with disc’s failing mid burn, reinstalling or using different burning software is a must as well.
If you have a removable drive always try and reseat the drive (eject and plug back in) this can often work, the drive may have moved in transit.
Issues with floppy drives are often terminal and will 90% of the time result in replacing the entire drive, more often faults with these drives are mechanical ones which causes the drive to no longer read discs.
Network and Modem:
To test your notebook for internal network and modem issues is quite simple. For modems just ensure everything is connected properly and you have an available phone line. Use Windows own HyperTerminal (Start/Programs/Accessories/Communications) to create a test dialup to your cell phone or additional phone line. If this still fails, uninstall and then reinstall the modem from Device Manager.
Most of the notebook modems are a separate little module that in most cases is easily replaced if after all this testing you still have no luck.
Network cards are generally a part of modern day motherboards so if yours is faulty you may want to look at a PCMCIA network card as a cheaper option.
If have a problem with your laptop's sound system there are a couple of ways to test your notebook to determine if it is indeed the sound chipset which is faulty.
If you have no sound through the speaker or headphone jack try reinstalling the sound device and checking all your sound properties, check to ensure the sound hasn’t been muted accidentally with a function key on the keyboard.
If you have sound via the headphone jack and not the speakers then the sound chipset is OK and you have an issue either with the speakers themselves or the headphone jack may be faulty and not switching back to the speakers when the headphone plug is removed.
You may find that after following these procedures to test your notebook that the component or drive seems OK, then it's time to look at your motherboard for faults.