Hello, the yellow light means your power supply is dead and you need to replace it. Can you tell me the Model/Series of this computer?
Example: Dell Dimension 2400
Thanks! Please replace the Power Supply to fix this problem and you will be back up and running in no time.
Power Supply Replacement
BEST OF LUCK!GOD BLESS!
The Power Supply Link I gave you was for a Dell Optiplex GX280. That is the correct one. If yours has a HP in it right now, then that could be the reason why this happened. You should have a DELL inside that case.
The only thing you need to remove from the hard drive, dvd/cd-rom is the White Power Cable and thats it.
It can be hard to remove those at first. You have to move it up and down and from left to right to losen it up, sometimes they can be a pain. But it will come out.
Sadly, since this part is old, you cant get it from dell anymore, and the newer models that are out will not work/fit into this unit. Ebay is your best bet and its cheaper.
Sure, there are 2 different types.
2) Mini Tower
The first CPU is for the Tower, and this one below....