You may have a bad Power On switch. The Power On switch is located inside the plastic Power On button.
This is a generic ATX power on switch, that I have found works in many computers,http://www.directron.com/atxswitch.html
Have you bypassed the Power On switch?
If you bypass the Power On switch, and the Power Supply comes on, you have a bad Power On switch.
If you bypass the Power On switch, and the Power Supply does Not come on, you have a bad Power Supply.
Sometimes a new Power Supply can be bad.
Make SURE the ATX main power cable is plugged in tightly.
(I have had an instance recently where I bypassed the Power On switch, and the Power Supply came on, but only as long as the jumper wire was in place. Remove jumper wire? Power Supply went off. Removed the jumper wire, then pressed the Power On button. The Power Supply came on )
Bypassing the Power On switch has nothing to do with the switch itself, or the wires to the switch.
A jumper wire is used in the connector for the ATX main power cable.
My sources indicate the ET1810 uses a 24-pin ATX main power cable.http://www.playtool.com/pages/psuconnectors/connectors.html#atxmain24
A jumper wire is used to connect the Green wire (Soft Power On. Also abbreviated as PS_ON) to ANY Black wire. (ALL Black wires are Ground wires)
Looking at the photo to the far right, you will see the Green wire goes down into a socket hole.
This is the Back of the connector.
The jumper wire goes down into the socket hole RIGHT NEXT to the Green wire.
The jumper wire has to go down into the socket hole pretty far.
(Approximately 1/2 inch)
At the end of the Green wire is a metal terminal. The jumper wire has to go down into the socket hole, far enough to touch that metal terminal.
Same thing for ANY socket hole with a Black wire.
(The Green wire is the Soft Power On wire. It is a 5 Volt DC wire. The Black wires are Ground wires.
The jumper makes a circuit from the Soft Power On wire to a Ground wire)
The jumper wire usually preferred is a paper clip straightened out, then bent into a U-shape.
The middle of the U is wrapped with black plastic electrical tape.
This is where your fingers hold the jumper wire.
One end of the jumper wire goes down into the socket hole with the Green wire.
The other end of the jumper wire goes down into a socket hole with ANY Black wire.
The contact is no more than 2 seconds.
My sources indicate the motherboard is an ECS MCP73VT-PM