Compared to other computer repairs, replacing internal CD-ROM and floppy disk drives is relatively easy. However, like any computer repair or upgrade, there are some potential complications, especially with certain computer models. If you don’t have any experience working inside computers, you may want to take the computer to a repair shop or purchase an external drive instead.
Floppy drives, both 3.5″ and 5.25″, are generally one of the easiest internal computer components to replace. Most standard drives are inexpensive to purchase (under $15), especially if they are used. All 3.5″ floppy drives being manufactured now, and most used drives, are designed to read both 1.44MB and old 720K 3.5″ disks. However, if purchasing an old used 3.5″ diskdrive, make sure that it can read 1.44MB disks, unless you need it for an older computer which can only support 720K disk drives – such as the Tandy 1000 RL. Many older Tandy computers use special non-standard 3.5″ disk drives which have different wiring. Another concern is that some Dell, Compaq and other brand-name computers only use 3.5″ disk drives designed to line up with the slot and button installed on their exteriors. Most laptops also need special thin disk drives. Almost all 5.25″ disk drives made after 1985 will work on any computer with a 5.25″ drive bay, as long as they support the appropriate disk density (1.2MB or 360K).
After acquiring an appropriate floppy drive which will fit and is compatible, the following steps will usually install it successfully. Unplug the computer and wait a couple minutes to be safe. Unscrew and remove the exterior casing or cover. Then unscrew the broken diskdrive, disconnect the power/data cables, and pull it out from its slot. Don’t throw it away yet, in case you find that there is a problem with the computer rather than the diskdrive. If you are replacing a 5.25″ diskdrive or CDROM with a 3.5″, you will need an adapter/mounting unit. Slide the new disk drive in, and connect the floppy drive power & data cables to it. Make sure the data cable is inserted the same way as it was before (not upside-down). Then screw in the new disk drive. Put the case or cover back on the computer and turn it on. It should be ready to use, unless you installed a different size (or density) drive, in which case you will need to change settings in the BIOS/setup program. If the light on the new drive stays on continously, you probably inserted the data ribbon cable upside-down. After you have tested the new drive to confirm that it is functioning properly, put the screws back in the case. If it still won’t function, you may need to replace the floppy data cable, the new diskdrive might have something wrong with it, or there could be more complex problems potentially involving the motherboard.
If you want to install 3.5″ and 5.25″ diskdrives in a computer with only one 5.25″ bay, you might consider purchasing a 5.25″/3.5″-combo floppy drive, which combines both types of diskdrive in a single compact unit. These can be found on eBay by searching for “3.5 5.25 combo”.
Replacing CD-ROM drives is similar, but can be slightly more complex. Most CD-ROM drives will fit any computer, as long as it has an open 5.25″ drive bay. Some compact desktop computers and laptops require special CD-ROM drives. If the computer doesn’t have a 5.25″ or special CD drive bay, you might want to consider purchasing an external CD-ROM drive instead. After finding a CD-ROM drive which will fit your computer, you will generally follow the same process as described above for replacing a floppy drive. However, there may be a small wire running from the CD-ROM drive to the sound card; you will have to make sure this is connected properly to the new drive. In some cases you will need special driver software to make a particular CD drive function in a computer.
If the above-described factors are taken into consideration and proper safety precautions followed, it should generally be an easy process to replace your CD or floppy disk drive.