Need to change input signal to 1440x900@60hz - Dell OptiPlex GX150 PC Desktop

Connect a known working DVD player by using a new HDMI cable to HDMI INPUT 1 and check for signal.
If you have a DISH or CABLE system box, connect that also with a new HDMI cable to HDMI input 2 or 3 and recheck for signal. Your T V remote will have an input selector to change between the different inputs on your
T V.

The 27" TV uses the same instructions as the 20", and I found the manual for you at the link below. Answering your question directly, here is the section of the instructions about changing input:
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Changing the TV's Input Normally, your TV displays the signal coming through the antenna terminal. However, if you've connected another component to your TV(such as a VCR & DVD) using the Video/Audio input,you will want to be able to view the signal from the component.To do this, you will need to switch from the ' TV ' input to the 'AV1-AV3, CVI' Input, as follows. 1 With the TV on, press the MENU button twice, then " Set-Up " menu will appear. 2 Use the WCHV buttons to select " Input ". 3 Press the CVOLB buttons to change the input source from ' TV ' to 'AV1, AV2, AV3, CVI'. 4 Wait 20 seconds, or press DISPLAY button or MENU button to return to normal TV viewing. * CVI means the Component Video Input (Y/ PB/ PR) from the DVD player etc.* Users can also select these input modes with the TV/AV button or the INPUT button on theremote controller. * On the AV1 mode , if you connect the S-VHS jack to your TV, "AV1" is changed to "S-VIDEO".
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The link to the manual is below.

Have you checked the wiring and changed the input on the LCD to the input you are using? If you are in input 1 then the LCD must be on input 1 to receive signal. Current tvs have several inputs and must be changed on the setup menu.

It has to be on the right channel. If you are supposed to be on channel 3, 61, 73, 113 (ask the satellite company which one you should be on) then you'll have to change the channel. If you are not supposed to be on a channel you have to find out which input you're supposed to be on (video 1, video 2, video 3, av 1, av 2, av 3, hdmi 1, hdmi 2, input 1, input 2, input 3 for example).

I would suggest you try to find a universal remote that has an "input" or "source" button and program that one to your tv. By pressing the "source" or "input" button, it will change the input to the tv. I hope this helps! -Der Strom

hook a different montor up to the same card and see if you get a signal. if you do change the input on the monitor not getting a signal. if this does not make the monitor get a signal your video input on the monitor is bad and needs o be replaced or repaired

I could be more specific if you described what brand/model you have but you need to change the input. Depending on where you have the cable input from the box, you'll need to set the tv to that input (video 1, hdmi1, component, etc).

You have changed the input to a selection that does not have a signal. Look at where the cable goes into the TV, this should show the name of that input, then change input back to that exact one via your remote.

Turn the television on and as soon as the screen turns on repeatily press the input button or change the input to whatever input you are using from a source device. As long as you change it to anything other than RGB.

Your television is essentially a big computer monitor with multiple inputs and a tuner. When using your computer and shutting it down the monitor will go in a power save mode. You don't need to shut off your monitor due to this power saving mode. When you power up your computer your monitor automatically turn on.

With the VIZIO and the RGB (computer) input the television will act just like a computer monitor. When you have a computer connected it will power down automatically when you shut off your computer. When you turn your computer on the VIZIO will automatically come out of standby mode. This is through RGB only.

This is normal operation for the VIZIO but can see confusing when nothing is connected to the RGB input. If you change your television input to RGB it will sense no signal on the input and will go into standby mode after about 5 - 10 seconds. If you were to send a signal to the television through RGB it would automatically kick on.

DO YOU MEAN WONT SWITCH FROM ANALOG TO DIGITAL!!!

THE ONLY WAY THIS WILL CHANGE IS IF YOU HAVE A DIGITAL INPUT SOURCE CONNECTED to this mointor like HDMI AS THIS MOINTOR AUTOMATICALLY SENSES ANALOG SIGNALS AND DIGITAL INPUT SIGNALS if a digital signal is available it will switch over if a digital input singal is not available you will only be able to use the analog option