On Fri, 25 Apr 2008 13:22:02 -0400, "Charlie Bress"
put finger to keyboard and composed:

My son has an E-Machine T3828 that will not power up. Unfortunately he is
around 100 miles away so I do not have more information. There were no
changes made to the PC that might have caused this.
At first glance it is easy to blame the P/S itself, but a new replacement
did not help.

A detail: He reports that with either supply there is a single LED on the
M/B that lights up. What controls this light?
On either P/S there is no other sign of life. No fans turn on.

What are the likely causes?

I have considered some. The power switch may have failed. Or the mechanical
link from the front panel to the switch.

Use a multimeter to monitor the PS_ON pin (pin 14, green) in the ATX
PS connector. It should go low when you press the front panel power
switch. The +5VSB pin (pin 9, purple) should measure +5V.

See http://pinouts.ru/Power/atxpower_pinout.shtml

If PS_ON doesn't go low, then something is wrong with the motherboard.
In this case it won't be the CPU or the RAM because neither are
powered in standby mode.

- Franc Zabkar
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