Monitor states No Signal, because it isn't receiving a Video Signal, from the computer.This can be from;A) A bad monitor cableB) Bad graphics card, or bad graphics chipset on the motherboardC) Computer isn't working. (May look, and sound as though it is)A1) If a flat LCD screen monitor (Digital), does it have a removable monitor cable, and do you have access to a working monitor cable of the same, to use for a test?A2) If not, do you have access to another KNOWN to be working monitor, and cable? Use it for a test.Or use your monitor and cable on a Known to be working computer.Monitor and monitor cable prove to be good?Next is go to the graphics card, or graphics chipset.B1) Graphics Chipset:Primer:Chip and Chipset are slang terms for I.C.Integrated Circuit,
http://en.wikipedia.org/wiki/Integrated_CircuitA graphics chipset is a GPU. Graphics Processing Unit,
http://en.wikipedia.org/wiki/GPUA GPU can be soldered directly to the motherboard. This is Integrated Graphics. (Another term used for Integrated Graphics is OnBoard Graphics.ON the motherBOARD)A GPU can also be soldered to a removable adapter card.This is a graphics card. Also known as a video card.If the graphics chipset is though to be bad, a graphics card is installed, (Drivers FIRST, then physically install the graphics card)You won't be using the motherboard, or Integrated Graphics anymore.You will be using the graphics of the graphics card. This is how a graphics chipset problem is cured.( If my data is correct, the eMachines T2240 Desktop PC uses an FIC VL35G motherboard.First International Computer {Inc},
http://www.ebay.com/itm/eMachine-HP-VL35G-865G-P4-Socket-478-uATX-Motherboard-/270778135974#vi-content Has an AGP expansion slot { Brown slot above the 3 white PCI slots } for a graphics card )C1) Computer not workingI think you can skip B1) and go here first.Reasoning is, that 80 to 90 percent of desktop computer failure, can be attributed to;Computer is dirty insideBad Power SupplyStart with computer is dirty inside. Computer on a table, computer unplugged from power, computer case open. Follow Anti-Static Precautions, check out the condition of the inside of the computer.[Anti-Static Precautions:Your body carries Static electricity. Static WILL fry out (Short Circuit) the delicate hardware components inside a computer.Computer on a table, computer unplugged from power, computer case open, TOUCH an unpainted surface, of the metal frame of the open computer case.SHOULD you leave your computer in the middle of working on it, be SURE to Touch the metal frame again upon your return ]If the computer is dirty inside use a can, or two of compressed air for computers, and clean it out.You may also need Q-tips to break the outside 'crust', by stirring it around. Then the compressed air can remove it better.[ You may wish to don a dust mask, and protective eye-wear ](Especially good for where the fan blades, meet the center hub of the fan; Edges of fan blades, and other areas )Insert the plastic straw provided on the side of the can, into the nozzle at the top of the can.Break the plastic lock tab off of the top of the nozzle.Start at the top left, or right inside corner.Spray air as a professional paint sprayer would. Squeeze the trigger in all the way as you start, let go when you reach the other side.Drop down a space, and spray air across again. Keep dropping down in rows, and spraying across until you reach the Processor Fan.The Processor Fan sits on top of a finned Heatsink. The Heatsink sits on top of the Processor.(The construction of the Heatsink is basically a small plate of metal, with tall, thin fins protruding from it. The plate of metal absorbs heat from whatever object it is placed against, { Processor in this case}, and the tall, thin fins absorb heat from the plate of metal.The tall, thin fins then radiate the heat away. The air flow from the Processor Fan, goes in-between the fins, and around the fins, and helps to carry heat away from the fins )Use special care to ensure that the fan is clean, and the Heatsink.However note that only use Short Bursts of air, when cleaning the Processor Fan.(Q-tips come in handy here)The Processor Fan is only designed to spin so fast. Spinning it faster than it was designed for (Long blasts of air), may shorten the life of the fan's bearings.Keep cleaning until you reach the bottom of the computer case. Tilt the top of the case towards you, clean the bottom of the case.The Power Supply is inside the computer case at the Top/Back.Clean through the ventilation holes of the Power Supply's case, as best as you can.Go around to the back, and clean the Fan, and surrounding cage. (Shroud)Come back to the inside once more, and give it one last 'dust off'.Also after time 'corrosion' develops on the contact pins, of the Ram Memory modules.The Ram Memory module/s should be removed, and a pencil eraser used to clean the contact pins.
http://en.wikipedia.org/wiki/File:Generic_DDR_Memory_%28Xytram%29.jpgThe Body of the ram memory module ('Stick'), is everywhere but the contact pins, at the bottom.A ram memory module should be handled by the Body.The Body is coated with a see-through protective plastic.Refrain from touching the gold plated contact pins.If an eraser is used on the end of a pencil, and not a solid eraser, refrain from letting the metal band touch the contact pins.Rub EACH contact pin. There are 184 pins. 92 on each side.(Doesn't take long)After cleaning use air to remove the eraser dust. You can use air from a can of compressed air, or air from your mouth will be sufficient.Reinstall the Ram Memory module/s.C2) Power SupplyCould have a weak voltage power rail. LED lights could light, and maybe fans spin, but Not enough power to turn the Processor on.A) IF all of the LED lights were on at once, they would use less than 1 Watt of power.B) EACH fan uses 2 to 3 Watts of power.C) A typical Processor can use 51 to 125 watts of power. Just depends on what Processor it is.There are 3 main voltages produced by the Power Supply.A) 3.3 Volts (DC) { Orange wires}B) 5 Volts (DC) { Red wires}C) 12 Volts (DC) { Yellow wires }{ALL Black wires are Ground wires }Test the Voltages to see if the Power Supply is good, (Multimeter), or use a KNOWN to be good, compatible power supply for a test unit.[Sometimes it's found that there may be an unused desktop computer around, that may have a working power supply, and it may work in the computer you are testing ]If no spare power supply is available, purchase an economical $30 unit for a replacement.{ATX}If you just want your information off of the harddrive, install it into an economical external enclosure, and remove your data.[ It is an IDE (PATA) harddrive. It is desktop size, which is 3 and 1/2 inches across in width. You need an IDE (PATA) 3.5 external enclosure.Example,
http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=1733195&CatId=2779 ]For additional questions please post in a Comment.Regards,joecoolvette