Computer does not power up. The green light on the back of the PS does not come on. I have 120 volts at the plug but when plugged into he power supply and push the power button on front of the computer nothing happens

Check all electrical connections at board check any moles plugs pins etc. if you have power going to board and no status light sounds like a bad board......

Have you figured what the problem with this is?

Check to make sure the power cord you are using is getting 120 volts and that it is plugged in properly to the pc. If you are sure your power cord is powering to 120 volts, plug it in to the computer and see if the power supply light (in the back of the computer) is coming on. If it is, then the power supply is good, if not, you need a new power supply unit. If your power supply does not have a power light on it, listen for the cooling fans to come on when you press the power button, if they don't, it is very possible that the power supply is bad and will need to be changed.

You'll need USB powered computer speakers such as these, they just plug into a USB port:
http://www.compusa.com/applications/SearchTools/item-details.asp?EdpNo=348887&CatId=4959

Or a set of speakers that plug into the pastel green jack in the back of the computer (or the phono jack on the side if it's a laptop) which also requires a power adapter that plugs into any regular 120 volt wall outlet:
http://www.compusa.com/applications/SearchTools/item-details.asp?EdpNo=4171798&CatId=4959

The greenlight is probably the UPS [Uninterruptible Power Source]. If the computer was shut down by a normal windows shutdown and the UPS remained plugged into the 120 Volt line and the computer's power supply plugged into the UPS and the UPS NOT turned off, there would still be 5 volt standby voltage applied to the computer's motherboard. ATX type computers never go completely off unless the power supply is turned off or unplugged.
That 5 volts would have to on steadily for the rest of the voltages from the supply to turn on.
If there is a reset button or on off switch at the back where your power cord plugs in toggle it back and forth. You can also try disconnecting the power supply and holding the power button in for about 15 seconds to discharge power.Leave it unplugged for a few minutes. Then try powering it back up again. If those don't work then you might have a bad power supply. They are not hard to replace.
Hope it helps

On the side of the unit is a small black flap that covers two prongs that you can plug a standard 110-120 volt extension cord into which will charge the unit. There are 3 read lights and 1 green lights on the top that lets you know when it is fully charged. The 12 volt charging cord is basically a cord that has 2 cigarette lighter plugs. One plugs into the unit and the other plugs into a power port/cigarette lighter plug.

my pc on problam frist time on after shutdown after con't power on the ps

Try the following possible solutions:
1. Unplug the power from your computer for 15 minutes.
2. If your computer is plugged in via a surge protector, plug your computer into the power outlet directly, maybe you are dealing with a faulty surge protector.
3. Near the plug where the power plugs into the back of your computer, there is a little switch where you can choose between 120 volts (USA) and 220 Volts (Europe) as input. Make your this did not inadvertently get changed to 220 Volts.

If neither one of these solves your problem, please let me know so I can assist you further. Also, how old is this computer?

Thanks for using the fixya forums!

Same here Once I plug the tv WS-55513 to 120 volts the green blinking timer blinks endlessly

It sounds like you hav blown a fuse. Hopefully just a fuse, connecting a 110 to a 240 will hurt.
Most equipment survives short term high voltage but sometimes it just can't take it.
if it's not the fuse then it's very likely damaged the power supply which will require the expert help of a technician..
good luck !
Ps the 321 is a very nice bit of kit..