Works for a few minutes then shuts down

These blinks [flashes] are fault indication (Error Codes). From the number of blinks occur at one time switch ON, you can get an idea about the faulty circuit section inside it. This will make repair easy. These are called blinking codes. Make sure about the exact number of blinking of the standby/power LED, by switching On & OFF the set, for at least two times. Count it carefully. If you wish to get some details, check the site linked here. It has details about blinking codes, and fault locating procedure, to many popular brand TVs and other devices
http://electro-medical.blogspot.com/

Blinking codes details of many popular brand TVs are given. Surf the site with patience. If blinks continue without any pause, the main board is faulty.
Counting of number of blinks to Philips TVs is entirely different to that of other brand TVs. It is not a direct count procedure. The site have details about how to count the number of LED blinks [Fault Codes] to Philips brand TVs are given; along with details of the faulty circuit location

Look at the pinout of the Front Panel header, of the eMachine W3400's motherboard.

The plastic front of the computer is the Front Panel.
The area of pins on the motherboard, that the cables (Wires) from the Front Panel connect to,
is the Front Panel header.

The motherboard for an eMachines W3400 desktop computer is an MSI ms-7145
(Micro Star International)

Orient the motherboard in your view so that we are both looking at it the same way.
Processor to the Top, Ram Memory slots to the Right, white PCI slots (3) to the Bottom.

JFP1 is the Front Panel header.
(Junction Front Panel 1)

JFP1 is on the Bottom Right corner. There are two columns of pins arranged vertically.
(The JFP1 header runs parallel to the Right side of the motherboard)

The Left side column of the JFP1 header is numbered Odd.
Starting at the Top and going Down, the pins are numbered;
1, 3, 5, 7, and 9

The Right side column is numbered Even.
Starting at the Top and going Down, the pins are numbered:
2, 4, 6, and 8.
There is NO Pin 10

A) Pins 1 and 3 are for the HarDDrive Activity LED light. (HDD)
If the LED light is dim will operating switch the wires around

B) Pins 5 and 7 are for the Reset switch. (Reset button)
> IF Used

C) Pin 9 is Not used. (NC. No Connection)

D) Pins 2 and 4 are for the Power On LED light (If dim switch the wires around)

E) Pins 6 and 8 are for the Power On switch. (Power On button)

Trace the wires back to the Power On switch. Even if it means temporarily removing part of the Front Panel to see.

Same with the LED lights.
See which wires go to the Power On LED, and HDD Activity LED. (Harddrive Activity LED)

Follow the 3 wires, and tell me where they go to on the Front Panel.
USB port?
Memory Card Reader?
Firewire port? (a1394)

1) The 9-pin header you are referring to, is the Front Panel header.

(Processor to the top, Ram Memory slots to the right, the Front Panel header is at the bottom right corner on the motherboard)

http://h10025.www1.hp.com/ewfrf/wc/document?docname=c00906129&lc=en&cc=de&dlc=&product=3397528

The plastic piece on the front of your computer is the Front Panel.
(Sometimes referred to as a Bezel)

Make a drawing, and notes as to where the individual wires go from that Front Panel header plug, (One-piece plug), to the Front Panel.

Follow the wires from the plug to the Front Panel.

Mark down where Each wire goes.

You may have to take components off of the Front Panel, in order to see exactly where Each wire goes.

For example:
You may have to remove the Power On button/switch assembly from the Front Panel.

It may have the Power On LED light, Power On button, (Switch), and perhaps the HarDDrive LED activity light, in this assembly.

The wires are color coded.

Generally, but not always, when two wires are used in conjunction with each other, (Example, Power On switch, or Power On LED light), the wires will be twisted together.

One wires insulation may be of a solid color, and the other wire may be white, with a stripe in the color of the solid wire.

Example: Wire with Red color, and wire twisted with it may be White, with a Red stripe.

See if these two wires go to the Power On switch.
End of example.

Follow each twisted pair of wires back down to the Front Panel header plug.
(One-piece plug)

See which socket holes the individual wires go to.
Mark it down in your drawing, and notes.

Mark where the individual socket holes plug onto each pin, in that Front Panel header. (9-pin header)

When you are finished, you will have a pinout for the Front Panel header on the Asus M2N68-LA motherboard, and will know where the individual wires go from your ThermalTake V3 computer case.

For the LED lights there is a Positive pin, ( + ), and a Ground pin. (Power On LED, and Harddrive activity LED, for example)

(Ground. Also referred to as the Negative pin. ( - )
This is DC Voltage)

If you have the polarity backwards, (Positive wire of the LED light is going to the Ground pin, Ground wire of the LED light is going to the Positive pin), the LED light will be dim.

(When operating)
Switch the wires around.

If you have questions, or need clarification of what I have stated above, simply state in a Comment.
(Believe upper right of your page)

The eMachines C2685 uses an FIC VC37GV motherboard. (First International Computer, Inc.)

http://www.motherboards.org/mobot/motherboards_d/FIC/VC37GV/

Here is the motherboard manual,

http://www.ime.org.uk/pdfs/vc37_vg31_b1_eng.pdf

After you click on the above link, give it up to 30 seconds to download. This is a PDF file.

Barring you cannot download the file, I will state the connections for the Front Panel header on the motherboard.
(Plus state the page to reference to, in case you can download)

View the first link, with the photo of the FIC VC37GV motherboard.

As shown, Processor is at the top, Ram Memory slots are to the right.

The Front Panel header is located at the very bottom right corner.

It is parallel to the outside edge of the motherboard. There are two rows of pins.
(Page 12)

The Front Panel header has 5 pins going across the top, and 4 pins across the bottom.

The top row of pins are numbered Odd.
The bottom row of pins are numbered Evenly.

On the Top row starting on the Right side, going towards the left, the pins are numbered 1, 3, 5, 7, and 9.

On the Bottom row starting on the Right side, going towards the left, the pins are numbered 2, 4, 6, and 8.

A) Pins 1 and 3 are for the HDD LED. (HarDDrive activity LED)

B) Pins 5 and 7 are for the Reset switch

C) Pins 2 and 4 are for a Dual Color Power On LED, if used.
Green goes to Pin 2. Yellow goes to Pin 4.

Otherwise Pin 2 is Positive, ( + ), and Pin 4 is Negative. ( - )

D) Pins 6 and 8 are for the Power On switch.
(PWR1, or SW1)

There is a small 3 pin header, just above the Front Panel header. (Page 12)

This is for a Power LED that has either two wires, or three wires.
The pins are numbered from Right to left.

Pin 1 is for the Power LED, and Pin 2 is for Ground, if using a two wire Power LED. (Not dual color)

Pin 1 is for the Power LED, and Pins 2 and 3 are for Ground (GND), if using a three wire Power LED.
(Page 13)

Ur Tuner signal board have problems or dead.Ur power LED light indicator stable for a few mins before the power LED light,and the OPC LED light indicators flashes?After the POWER light and OPC light indicators flashes,just push the power button again for the power recycles again.Probally have to pushes the power button 3 or 4 for power light and opc light indicators flashes,the LCD backlght will lght up and work.Sharp tv have this problems alot,very common in Sharp LCD tvs.

A fast check to determine whether you have a problem with the power adapter, power cord or the laptop's battery is to turn off the laptop, remove the battery, connect the power adapter, turn on the laptop & see if it works.
If the laptop works directly from the power adapter with the battery removed, then the power adapter is good. In this case we can suspect that the battery is defective.

I still have that problem. I calle Mfr and also spoke to repair shops recommended by them and they said they estimate a cost of 300-400$ or so approx. I am waiting to buy a new LCD which could be few 100 more but at least dont have to live with the old one and keep spending money...

regards

GOOD DAY;

THIS COULD BE YOUR PROBLEM:

1. Red status LED, self-diagnosis error 44, check for open F9A06 on the Power PCB part # 283P128050 on the Power PCB 2. Red lamp LED, self diagnosis error 34. Check for 5-volts DC at J-9 connector pin 1 and 2 on the Engine Driver PCB if missing replace the Power PCB part # 930B921002 3. LED stops blinking after 70 seconds of plug in but will not power on. This model is equipped with a keyboard lock feature, this can be mistaken as a no power condition. To unlock the keyboard press and hold the "menu" button on the front panel for 10 seconds 4. LED stops blinking after 70 seconds of plug in but will not power on. Check for 3.2 volts DC at connector LE pin 3 and 4 on the Control PCB, if low suspect problems with the switches/buttons on the Control PCB part # 935D776001 5. LED stops blinking after 70 seconds of plug in but will not power on. Keyboard is not locked and key inputs at connector LE pin 3 and 4 check good. Suspect the E2P PCB part # 934C121001 6. (LED does not stop blinking after plug in) Disconnect the USB connector from the card reader to the front from the Chassis, if the LED stops blinking after 70 seconds replace the Card Reader part # 299P271010. 7. (LED does not stop blinking after plug in) Disconnecting the USB connector from the Card Reader did not help. Remove connector FC from the FMT PCB and plug the unit in, if the LED stops blinking after 70 seconds with FC removed suspect a problem on the FMT PCB (part # 930B924002), if the LED keeps blinking with connector FC removed suspect a problem on the DM PCB (part # 934C116002). 8. (LED does not stop blinking after plug in) On the DM PCB (part # 934C116002) check C81A2, C81A3, C81B3 and C81B4 (1000 UFD, 16V, 105C), if any are bad, replace all of them with part # 181P734030 (680 uFD, 16V, 105C). See Service Tip VS-78A 9. (LED does not stop blinking after plug in) On the FMT PCB (part # 930B924002) check C8F19, C8F21, C8F22, and C8F27 (16V 1000 UFD 105C), if any are bad, replace all of them with part # 181P734030 (680 uFD, 16V, 105C). Good Luck, big IRISH.

I have had this same problem twice in the past 3 months. So far both times I've been able to get it back after a week or two. I'm not sure what works, but unplugging and detaching the antenna and cable and waiting a few days seems to be the key. In both instances, I unplugged it for a few days then plugged it in for a few days and repeated the processes until I eventually got the steady red led. Both times prior to the red led the led would flash red then green and make a clickiing noise for several hours before I was able to get it working again.