USB WON'T WORK ON EMACHINES W3050

SOURCE: card reader on emachine t3642 cannot start (error 10)

With a card installed in card reader that is normal operation.
Mark

SOURCE: usb port not working

Call acer let them replace the systemboard of your E machine.

SOURCE: emachines W3050

Buy a new PCI ethernet card and install it.

SOURCE: All USB ports on my emachines T6542 do not work

try to see the BIOS SET UP if the USB port are in enbled status..

if its not,, enabled them...

and see the connection of the USB port into your motherboard if it connect properly..

SOURCE: My T6216 Emachine stopped working. None of the

Even if those things power up doesn't mean your PSU is still good.
In particular the PSU in eMachines are known to be cheap/bad and one of the first things to go out.

If you have access to one try another ATX power supply.
You don't have to remove the old one just to test.

1) Unplug the existing PSU power cable from the back.
2) Remove all it's connections (MB, drives, etc).
3) Plug the other PSU in with just the two MB connections (the main, and 12v one), skipping any drives for now.
It's probably ok if the test one is not touching, but I like to put the PC on the side with the test PSU setting on top where the original one is making sure it has good contact with the case to make sure it's grounded.
4) Now plug the AC into the test PSU and power it up.

If it still dosn't power up it's probably MB, or CPU.
You could also unplug it again (you always want to unplug the PSU when doing anything, the power is always on), and try removing any add on cards (like your wireless card), and try again.

If it does power up (you get a POST screen), unplug PSU again, now plug-in drives, then AC back and see if it will boot up.