The power supply on my Dell Inspiron computer failed a few months ago and I had to replace it. The power supply in this model is on the low end of the performance and quality spectrum. It is rated at 300W but appears to be under powered for this system. I have a degree in Computer Science and from my experience it is always better to have plenty of reserve power for your system. I purchased the WPO-480Q 480W power supply for my system from SWS Electronics. This power supply requires modification to the mount and Serial Advanced Technology Attachment (SATA) cables for proper installation.
As you are looking forward at your computer from the back, remove the two screws on the right hand back edge of the case that secure the side cover. The screws should be hand tight. The cover is on the right if you are looking from behind or the left if you are looking from the front. Slide the cover back to remove it. The power supply will be the large square device mounted at the top aft section of the computer case. There will be a large wire harness coming from the supply branching out to the motherboard, DVD/CD ROM, and hard drive. Disconnect all of the cables making note of their location. Remove any tie straps that maybe securing the harness to the case. Remove the four screws at the back of the case securing the supply. Carefully slide the supply back slightly and then to the side towards the removed cover to work it out of the case.
Remove your WPO-480Q power supply from the packaging and inspect it to make sure there is no damage to it and nothing is missing. The SATA power cables on this supply are not long enough to reach between your DVD/CD ROM and hard drive if they are mounted in the factory locations. There are two options to correct this problem. Extension SATA cables can be purchased for less than $10 typically at any reputable computer store. I recommend TigerDirect. If you are not computer savvy, it may be best to consult with professionals at your local computer store before purchasing the cables to ensure that you have the correct product. Only one extension cable will be required because the new cables will connect to one device but not both. The other option is to cut the SATA cable off of your old power supply and splice it to the new supply. This is a detailed process that I will cover in a future article. Next you will need to mount your power supply into the case in the reverse order of removal. The mount holes on the case won’t align with the holes on the supply and will require re-drilling. Align the power supply with the case mounts and hold it in place as you carefully drill four new holes in the supply with a 1/8″ drill bit. After the holes are drilled, installation is the reverse of removal.