The battery light on the tower stays on.

relay buzzing maybe thats your fault

You need a new A/C extenal power pack - yours has failed - the beeping sound it battery being totally flat.

Since you have tried different power cables its seems to be the issue with the SMPS. The SMPS needs to be replaced.

You can test the SMPS
check this LINK:
http://www.jestineyong.com/?p=267

Hi,
The problem is due loose memory sticks or mismatched memory sticks.
You need to open the computer tower and reseat the memory modules on the machine to fix the issue.

How to do it ? follow the link below
http://support.dell.com/support/edocs/systems/dim5150/en/sm/parts1.htm#wp1364711

Thanks for using fixya
proton

If the service engine light is on. Take it to a autozone and get it scanned. It might be the fuel pump..

The yellow or red light would mean a control board that is bad or going bad. The buzzing sound could just be the transformer not uncommon to hear a buzzing sound from the transformer.

the hard drive isnt working.

Hi there and welcome to FixYa!

Sounds like you have a build up of dust collected in the fan of your computer which will cause the sound you described.

If you are comfortable with computers, go ahead and open up with the computer tower and use some of the compressed air cleaner you buy at Best Buy or Office Depot to clean it out. This should solve the problem :)

If you are not comfortable, take it into a computer repair store and explain the situation. It should be a very quick, inexpensive fix on their part.

Hope this helps and have a Happy Holiday!
-TJ

Personally, I think your CPU is to far to come back. I'd trade it in.

Is the buzzing coming from the back of the TV, staying loud even when the volume is turned all the way down, or is it coming from the speakers?