adeplus2

I can't varify if it's from another system or computer. I can only assume their pre-owned.

I tried your advice again, the result was the same. No POST beeps but with the new motherboard and power supply units. I don't know what else to do, could it be wire faults? Or just a faulty computer?

I can varify, that the new motherboard contains a speaker.

The motherboard is some what the same, the wire slots for the hard drive have been changed, but it is the same motherboard. There is no graphics card I could find, it is intergrated from what I can tell. However I did try to install one, as there is a slot for it, but failed as there wasn't enough space for it. I believe the hard drive does work, as it spins when its turned on.

I have tested the computer with your advice, the fans do spin (there is only one), I can confirm the hard drive does spin and there are no beeps when the RAM is taken out. Does that mean the RAM is at fault?

Hi KenB Update so far, changed motherboard and PSU and the same problem persists. The machine switches on seems to be running fine, there are no beeps, but the monitor remains blank with the orange instead of green light indicating nothing is coming through. We have tested the monitor, it is fine and swapped the monitor cable just in case. The machine simply won't boot up at all with either old or new MB or PSU, any other ideas appreciated? -Edit- Would it help if I took a picture of the inside and posted it on this thread?

Hi KenB, I followed the tutorial to my best, stripping the computer to what your specifics said, and no beep was heard. All cards and wires were disconnected from the motherboard (that I can see and reach) and the disc drive and hard drive were fully disconnected from the motherboard. My end result was no beep heard, if being either the PSU or Motherboard is at fault, are any costs needed to make sure the computer is fully functional? Or can I simply twist something and a spark of life will be sent through the machine?

Hi KenB This is secondhand computer that was working well until this point. The machine turns on and seems to power up fine, just nothing on the screen. It did beep several times it quick order, but does not now, I have just powered it up and there are no beeps now,

Hi all, I recently bought a Dell Optiplex 755, recently a fault has occured with it, which no video is shown on the monitor. I have verified the monitor and the connection cable is not at fault, as I have tested with other devices and they work with it. I have reset everything inside the box but again nothing is appearing on the screen, the fan is working and a a light is showing on the motherboard so power is getting through. If anyone is able to help, please do so, I have no idea on the problem and wish to spend as little as possible on repairs.