No signal input

Morning everyone , just built my first custom pc build and it all of the parts turned on and i installed the os and all of the driver :) The problem is that when i switched cases due to the old one getting damaged i keep getting no signal input .
I have done the basic troubleshooting tips such as take out the gpu and test out the built in graphics slots , use hdmi and vga wires , replace the motherboard , take out the ram , take out gpu and all of it still doesn't worked . I have put in a new graphics card and a new Motherboard and it still keeps saying no signal input when i connect the pc to a display .
The pc is wired correctly a the pc turns on with all of the lights normally and doesn't ever restart .
Any help would be much appreciated . Thanks in advance :)
6 answers Last reply
More about signal input
  1. 1.) post system specs
    2.) did you motherboard POST?
    3.) did your GPU's Fan turn on?
    4.) did you check for a defective screen or wires?
    5.) do you have another computer to work with?
  2. Hi the specs of the machine are as follows :
    Motherboard :Asrock N68C-S UCC GeForce 7025 Socket AM2+ VGA Out 6 Channel Audio mATX
    processor :AMD Athlon II X4 640 Socket AM3 3GHz 2MB L2 Cache
    GPU : Asus GT220 1GB GDDR2 DVI VGA HDMI Out PCI-E Graphics Card
    Case :Casecom MA-1199 Shiny Silver with Black Front MATX Tower Case
    PSU:ACE 620W PSU 12cm Fan - 20+4pin 2x SATA
    Sound card : Creative Sound Blaster Audigy SE 7.1 OEM PCI
    HDD : Hitachi 2TB 3.5" Deskstar Coolspin SATA-III 6GB/s Hard Drive - 5900rpm 32MB Cache
    CD drive : LiteOn iHAS124-19 24x DVD±RW DL & RAM SATA Optical Drive
    Ram : Corsair 2GB DDR3 1333MHz & Kingston 4GB DDR3 1066MHz

    Sorry about this but i don't understand what you mean by the motherboards Post :/ sorry
    and yeah i changed the monitor a few times and it still kept saying that there is no signal input , i also rewired everything and then chasnged all of the wires with new fresh ones and rewired it all again . Ill check the gpu fan and update you by tonight . Thank you for your help it really is appreciated :)
  3. also, can you switch back to the old case and have the computer run perfectly?
  4. The pc was working perfectly when it was in the old case but i cant go back to the old one as i have disposed of it :/ But in the old one i had installed the os , installed the drivers and software using my main screen that is no longer working :(
  5. The POST that Foverosiv is referring to is the POwerup Self /b]Test that a system does before it boots. If the POST passes, you should hear a single short beep.

    There are two things that I do not like in your system specs. First, the power supply. I have never heard of the brand "Ace". Second, you have mixed memory brands and speeds. Try removing one memory stick and see what happens.

    Breadboard the system and build and test it in sections. Then, if it works outside the case, you know you have something wrong with the case.

    The following is an expansion of my troubleshooting tips in the breadboarding link in the "Cannot boot" thread.

    I have tested the following beep patterns on Gigabyte, eVGA, and ECS motherboards. Other BIOS' may be different, but they all use a single short beep for a successful POST.

    Breadboard - that will help isolate any kind of case problem you might have.

    Breadboard with just motherboard, CPU & HSF, case speaker, and PSU.

    Make sure you plug the CPU power cable in. The system will not boot without it.

    I always breadboard a new build. It takes only a few minutes, and you know you are putting good parts in the case once you are finished.

    You can turn on the PC by momentarily shorting the two pins that the case power switch goes to. You should hear a series of long, single beeps indicating memory problems. Silence indicates a problem with (in most likely order) the PSU, motherboard, or CPU. Remember, at this time, you do not have a graphics card installed so the load on your PSU will be reduced.

    If no beeps:
    Running fans and drives and motherboard LED's do not necessarily indicate a good PSU. In the absence of a single short beep, they also do not indicate that the system is booting.

    At this point, you can sort of check the PSU. Try to borrow a known good PSU of around 550 - 600 watts. That will power just about any system with a single GPU. If you cannot do that, use a DMM to measure the voltages. Measure between the colored wires and either chassis ground or the black wires. Yellow wires should be 12 volts. Red wires: +5 volts, orange wires: +3.3 volts, blue wire : -12 volts, violet wire: 5 volts always on. Tolerances are +/- 5% except for the -12 volts which is +/- 10%.

    The gray wire is really important. It should go from 0 to +5 volts when you turn the PSU on with the case switch. CPU needs this signal to boot.

    You can turn on the PSU by completely disconnecting the PSU and using a paperclip or jumper wire to short the green wire to one of the neighboring black wires.

    A way that might be easier is to use the main power plug. Working from the back of the plug where the wires come out, use a bare paperclip to short between the green wire and one of the neighboring black wires. That will do the same thing with an installed PSU. It is also an easy way to bypass a questionable case power switch.

    This checks the PSU under no load conditions, so it is not completely reliable. But if it can not pass this, it is dead. Then repeat the checks with the PSU plugged into the computer to put a load on the PSU.

    If the system beeps:
    If it looks like the PSU is good, install a memory stick. Boot. Beep pattern should change to one long and several short beeps indicating a missing graphics card.

    Silence, long single beeps, or series of short beeps indicate a problem with the memory. If you get short beeps verify that the memory is in the appropriate motherboard slots.

    Insert the video card and connect any necessary PCIe power connectors. Boot. At this point, the system should POST successfully (a single short beep). Notice that you do not need keyboard, mouse, monitor, or drives to successfully POST.
    At this point, if the system doesn't work, it's either the video card or an inadequate PSU. Or rarely - the motherboard's PCIe interface.

    Now start connecting the rest of the devices starting with the monitor, then keyboard and mouse, then the rest of the devices, testing after each step. It's possible that you can pass the POST with a defective video card. The POST routines can only check the video interface. It cannot check the internal parts of the video card.
  6. Hi thanks for the reply ill breadboard it tonight and will post up the results , thank you for the help :)
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