No signal to monitor and possible PSU issue or gpu

Okay here's my situation. With my first build I would have to unplug my psu and plug it back in a few times for it to stay turned on. Now for my second build (which is just an upgrade from my first build) I turn my computer on, no signal to my monitor. The MEMok light goes red then turns off, then 3 out of the 4 red GPU lights turn on. I then will try and unplug the GPU and plug it back in until I get no red lights. Then there is still no signal. Also it doesn't stay like that for long if I restart it once it goes back to the red light dance. I tried both my monitor and hdtv. I have checked every power connection and reconnected each one. I also reseated the ram.
First Build:
MotherBoard- M4A8TD/USB3
CPU- Amd Phenom II x4 965 black edition CORSAIR H40 120mm High Performance Liquid CPU Cooler
PSU- OCZ / GameXStream / 700-Watt / ATX / 120mm Fan / SATA Ready / SLI Ready / EPS / Active PFC / Power Supply
GPU- Ati Radeon HD 4870
RAM- DDR3 2g x2 HDD- sata 1TB
ROM- Broken DVD drive

Second Build:
MotherBoard- M4A8TD/USB3
CPU- AMD Phenom II x4 965 Black Edition - CORSAIR H40 120mm High Performance Liquid CPU Cooler
PSU- OCZ / GameXStream / 700-Watt / ATX / 120mm Fan / SATA Ready / SLI Ready / EPS / Active PFC / Power Supply
GPU- Ati Radeon HD 4870
RAM- DDR3 2g x2
HDD- SSD 120g and 2T HDD
ROM- Blueray Burner
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More about signal monitor issue
  1. Any help would be greatly appreciated.
  2. First build definetly something wrong and points to the PSU! Second build the PSU might have gotten worse! Then again it could be the GPU but can it be tested in a different computer?
  3. No not at all. I was thinking about grabbing a new psu and gpu anyways. I'll grab them from newegg tonight or tomorrow.
  4. Having two similar systems is very handy when one goes down. I recommend that you mark the parts from each system before you start swapping parts. It's really frustrating to move parts, notice a change in the symptoms, then realize that you lost track of the parts. That happened to me - once - about 45 years ago.

    So, mark the parts, then start troubleshooting.

    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 (standby power supply): 5 volts always on. The green wire should also have 5 volts on it. It should go to 0 volts when you press the case power button, then back to 5 volts when you release the case power switch. 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.
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